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rsync(1) User Commands rsync(1)

NAME

 rsync - a fast, versatile, remote (and local) file-copying tool

SYNOPSIS

 Local:
 rsync [OPTION...] SRC... [DEST]
 Access via remote shell:
 Pull:
 rsync [OPTION...] [USER@]HOST:SRC... [DEST]
 Push:
 rsync [OPTION...] SRC... [USER@]HOST:DEST
 Access via rsync daemon:
 Pull:
 rsync [OPTION...] [USER@]HOST::SRC... [DEST]
 rsync [OPTION...] rsync://[USER@]HOST[:PORT]/SRC... [DEST]
 Push:
 rsync [OPTION...] SRC... [USER@]HOST::DEST
 rsync [OPTION...] SRC... rsync://[USER@]HOST[:PORT]/DEST)
 Usages with just one SRC arg and no DEST arg will list the source files
 instead of copying.
 The online version of this manpage (that includes cross-linking of
 topics) is available at <https://download.samba.org/pub/rsync/rsync.1 >.

DESCRIPTION

 Rsync is a fast and extraordinarily versatile file copying tool. It
 can copy locally, to/from another host over any remote shell, or
 to/from a remote rsync daemon. It offers a large number of options
 that control every aspect of its behavior and permit very flexible
 specification of the set of files to be copied. It is famous for its
 delta-transfer algorithm, which reduces the amount of data sent over
 the network by sending only the differences between the source files
 and the existing files in the destination. Rsync is widely used for
 backups and mirroring and as an improved copy command for everyday use.
 Rsync finds files that need to be transferred using a "quick check"
 algorithm (by default) that looks for files that have changed in size
 or in last-modified time. Any changes in the other preserved
 attributes (as requested by options) are made on the destination file
 directly when the quick check indicates that the file's data does not
 need to be updated.
 Some of the additional features of rsync are:
 o support for copying links, devices, owners, groups, and
 permissions
 o exclude and exclude-from options similar to GNU tar
 o a CVS exclude mode for ignoring the same files that CVS would
 ignore
 o can use any transparent remote shell, including ssh or rsh
 o does not require super-user privileges
 o pipelining of file transfers to minimize latency costs
 o support for anonymous or authenticated rsync daemons (ideal for
 mirroring)

GENERAL

 Rsync copies files either to or from a remote host, or locally on the
 current host (it does not support copying files between two remote
 hosts).
 There are two different ways for rsync to contact a remote system:
 using a remote-shell program as the transport (such as ssh or rsh) or
 contacting an rsync daemon directly via TCP. The remote-shell
 transport is used whenever the source or destination path contains a
 single colon (:) separator after a host specification. Contacting an
 rsync daemon directly happens when the source or destination path
 contains a double colon (::) separator after a host specification, OR
 when an rsync:// URL is specified (see also the USING RSYNC-DAEMON
 FEATURES VIA A REMOTE-SHELL CONNECTION section for an exception to this
 latter rule).
 As a special case, if a single source arg is specified without a
 destination, the files are listed in an output format similar to
 "ls -l".
 As expected, if neither the source or destination path specify a remote
 host, the copy occurs locally (see also the --list-only option).
 Rsync refers to the local side as the client and the remote side as the
 server. Don't confuse server with an rsync daemon. A daemon is always
 a server, but a server can be either a daemon or a remote-shell spawned
 process.

SETUP

 See the file README.md for installation instructions.
 Once installed, you can use rsync to any machine that you can access
 via a remote shell (as well as some that you can access using the rsync
 daemon-mode protocol). For remote transfers, a modern rsync uses ssh
 for its communications, but it may have been configured to use a
 different remote shell by default, such as rsh or remsh.
 You can also specify any remote shell you like, either by using the -e
 command line option, or by setting the RSYNC_RSH environment variable.
 Note that rsync must be installed on both the source and destination
 machines.

USAGE

 You use rsync in the same way you use rcp. You must specify a source
 and a destination, one of which may be remote.
 Perhaps the best way to explain the syntax is with some examples:
 rsync -t *.c foo:src/
 This would transfer all files matching the pattern *.c from the current
 directory to the directory src on the machine foo. If any of the files
 already exist on the remote system then the rsync remote-update
 protocol is used to update the file by sending only the differences in
 the data. Note that the expansion of wildcards on the command-line
 (*.c) into a list of files is handled by the shell before it runs rsync
 and not by rsync itself (exactly the same as all other Posix-style
 programs).
 rsync -avz foo:src/bar /data/tmp
 This would recursively transfer all files from the directory src/bar on
 the machine foo into the /data/tmp/bar directory on the local machine.
 The files are transferred in archive mode, which ensures that symbolic
 links, devices, attributes, permissions, ownerships, etc. are preserved
 in the transfer. Additionally, compression will be used to reduce the
 size of data portions of the transfer.
 rsync -avz foo:src/bar/ /data/tmp
 A trailing slash on the source changes this behavior to avoid creating
 an additional directory level at the destination. You can think of a
 trailing / on a source as meaning "copy the contents of this directory"
 as opposed to "copy the directory by name", but in both cases the
 attributes of the containing directory are transferred to the
 containing directory on the destination. In other words, each of the
 following commands copies the files in the same way, including their
 setting of the attributes of /dest/foo:
 rsync -av /src/foo /dest
 rsync -av /src/foo/ /dest/foo
 Note also that host and module references don't require a trailing
 slash to copy the contents of the default directory. For example, both
 of these copy the remote directory's contents into "/dest":
 rsync -av host: /dest
 rsync -av host::module /dest
 You can also use rsync in local-only mode, where both the source and
 destination don't have a ':' in the name. In this case it behaves like
 an improved copy command.
 Finally, you can list all the (listable) modules available from a
 particular rsync daemon by leaving off the module name:
 rsync somehost.mydomain.com::

COPYING TO A DIFFERENT NAME

 When you want to copy a directory to a different name, use a trailing
 slash on the source directory to put the contents of the directory into
 any destination directory you like:
 rsync -ai foo/ bar/
 Rsync also has the ability to customize a destination file's name when
 copying a single item. The rules for this are:
 o The transfer list must consist of a single item (either a file
 or an empty directory)
 o The final element of the destination path must not exist as a
 directory
 o The destination path must not have been specified with a
 trailing slash
 Under those circumstances, rsync will set the name of the destination's
 single item to the last element of the destination path. Keep in mind
 that it is best to only use this idiom when copying a file and use the
 above trailing-slash idiom when copying a directory.
 The following example copies the foo.c file as bar.c in the save dir
 (assuming that bar.c isn't a directory):
 rsync -ai src/foo.c save/bar.c
 The single-item copy rule might accidentally bite you if you
 unknowingly copy a single item and specify a destination dir that
 doesn't exist (without using a trailing slash). For example, if
 src/*.c matches one file and save/dir doesn't exist, this will confuse
 you by naming the destination file save/dir:
 rsync -ai src/*.c save/dir
 To prevent such an accident, either make sure the destination dir
 exists or specify the destination path with a trailing slash:
 rsync -ai src/*.c save/dir/

SORTED TRANSFER ORDER

 Rsync always sorts the specified filenames into its internal transfer
 list. This handles the merging together of the contents of identically
 named directories, makes it easy to remove duplicate filenames. It can,
 however, confuse someone when the files are transferred in a different
 order than what was given on the command-line.
 If you need a particular file to be transferred prior to another,
 either separate the files into different rsync calls, or consider using
 --delay-updates (which doesn't affect the sorted transfer order, but
 does make the final file-updating phase happen much more rapidly).

MULTI-HOST SECURITY

 Rsync takes steps to ensure that the file requests that are shared in a
 transfer are protected against various security issues. Most of the
 potential problems arise on the receiving side where rsync takes steps
 to ensure that the list of files being transferred remains within the
 bounds of what was requested.
 Toward this end, rsync 3.1.2 and later have aborted when a file list
 contains an absolute or relative path that tries to escape out of the
 top of the transfer. Also, beginning with version 3.2.5, rsync does
 two more safety checks of the file list to (1) ensure that no extra
 source arguments were added into the transfer other than those that the
 client requested and (2) ensure that the file list obeys the exclude
 rules that were sent to the sender.
 For those that don't yet have a 3.2.5 client rsync (or those that want
 to be extra careful), it is safest to do a copy into a dedicated
 destination directory for the remote files when you don't trust the
 remote host. For example, instead of doing an rsync copy into your
 home directory:
 rsync -aiv host1:dir1 ~
 Dedicate a "host1-files" dir to the remote content:
 rsync -aiv host1:dir1 ~/host1-files
 See the --trust-sender option for additional details.
 CAUTION: it is not particularly safe to use rsync to copy files from a
 case-preserving filesystem to a case-ignoring filesystem. If you must
 perform such a copy, you should either disable symlinks via --no-links
 or enable the munging of symlinks via --munge-links (and make sure you
 use the right local or remote option). This will prevent rsync from
 doing potentially dangerous things if a symlink name overlaps with a
 file or directory. It does not, however, ensure that you get a full
 copy of all the files (since that may not be possible when the names
 overlap). A potentially better solution is to list all the source files
 and create a safe list of filenames that you pass to the --files-from
 option. Any files that conflict in name would need to be copied to
 different destination directories using more than one copy.
 While a copy of a case-ignoring filesystem to a case-ignoring
 filesystem can work out fairly well, if no --delete-during or --delete-
 before option is active, rsync can potentially update an existing file
 on the receiving side without noticing that the upper-/lower-case of
 the filename should be changed to match the sender.

ADVANCED USAGE

 The syntax for requesting multiple files from a remote host is done by
 specifying additional remote-host args in the same style as the first,
 or with the hostname omitted. For instance, all these work:
 rsync -aiv host:file1 :file2 host:file{3,4} /dest/
 rsync -aiv host::modname/file{1,2} host::modname/extra /dest/
 rsync -aiv host::modname/first ::extra-file{1,2} /dest/
 Note that a daemon connection only supports accessing one module per
 copy command, so if the start of a follow-up path doesn't begin with
 the modname of the first path, it is assumed to be a path in the module
 (such as the extra-file1 & extra-file2 that are grabbed above).
 Really old versions of rsync (2.6.9 and before) only allowed specifying
 one remote-source arg, so some people have instead relied on the
 remote-shell performing space splitting to break up an arg into
 multiple paths. Such unintuitive behavior is no longer supported by
 default (though you can request it, as described below).
 Starting in 3.2.4, filenames are passed to a remote shell in such a way
 as to preserve the characters you give it. Thus, if you ask for a file
 with spaces in the name, that's what the remote rsync looks for:
 rsync -aiv host:'a simple file.pdf' /dest/
 If you use scripts that have been written to manually apply extra
 quoting to the remote rsync args (or to require remote arg splitting),
 you can ask rsync to let your script handle the extra escaping. This
 is done by either adding the --old-args option to the rsync runs in the
 script (which requires a new rsync) or exporting RSYNC_OLD_ARGS=1 and
 RSYNC_PROTECT_ARGS=0 (which works with old or new rsync versions).

CONNECTING TO AN RSYNC DAEMON

 It is also possible to use rsync without a remote shell as the
 transport. In this case you will directly connect to a remote rsync
 daemon, typically using TCP port 873. (This obviously requires the
 daemon to be running on the remote system, so refer to the STARTING AN
 RSYNC DAEMON TO ACCEPT CONNECTIONS section below for information on
 that.)
 Using rsync in this way is the same as using it with a remote shell
 except that:
 o Use either double-colon syntax or rsync:// URL syntax instead of
 the single-colon (remote shell) syntax.
 o The first element of the "path" is actually a module name.
 o Additional remote source args can use an abbreviated syntax that
 omits the hostname and/or the module name, as discussed in
 ADVANCED USAGE.
 o The remote daemon may print a "message of the day" when you
 connect.
 o If you specify only the host (with no module or path) then a
 list of accessible modules on the daemon is output.
 o If you specify a remote source path but no destination, a
 listing of the matching files on the remote daemon is output.
 o The --rsh (-e) option must be omitted to avoid changing the
 connection style from using a socket connection to USING RSYNC-
 DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION.
 An example that copies all the files in a remote module named "src":
 rsync -av host::src /dest
 Some modules on the remote daemon may require authentication. If so,
 you will receive a password prompt when you connect. You can avoid the
 password prompt by setting the environment variable RSYNC_PASSWORD to
 the password you want to use or using the --password-file option. This
 may be useful when scripting rsync.
 WARNING: On some systems environment variables are visible to all
 users. On those systems using --password-file is recommended.
 You may establish the connection via a web proxy by setting the
 environment variable RSYNC_PROXY to a hostname:port pair pointing to
 your web proxy. Note that your web proxy's configuration must support
 proxy connections to port 873.
 You may also establish a daemon connection using a program as a proxy
 by setting the environment variable RSYNC_CONNECT_PROG to the commands
 you wish to run in place of making a direct socket connection. The
 string may contain the escape "%H" to represent the hostname specified
 in the rsync command (so use "%%" if you need a single "%" in your
 string). For example:
 export RSYNC_CONNECT_PROG='ssh proxyhost nc %H 873'
 rsync -av targethost1::module/src/ /dest/
 rsync -av rsync://targethost2/module/src/ /dest/
 The command specified above uses ssh to run nc (netcat) on a proxyhost,
 which forwards all data to port 873 (the rsync daemon) on the
 targethost (%H).
 Note also that if the RSYNC_SHELL environment variable is set, that
 program will be used to run the RSYNC_CONNECT_PROG command instead of
 using the default shell of the system() call.

USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION

 It is sometimes useful to use various features of an rsync daemon (such
 as named modules) without actually allowing any new socket connections
 into a system (other than what is already required to allow remote-
 shell access). Rsync supports connecting to a host using a remote
 shell and then spawning a single-use "daemon" server that expects to
 read its config file in the home dir of the remote user. This can be
 useful if you want to encrypt a daemon-style transfer's data, but since
 the daemon is started up fresh by the remote user, you may not be able
 to use features such as chroot or change the uid used by the daemon.
 (For another way to encrypt a daemon transfer, consider using ssh to
 tunnel a local port to a remote machine and configure a normal rsync
 daemon on that remote host to only allow connections from "localhost".)
 From the user's perspective, a daemon transfer via a remote-shell
 connection uses nearly the same command-line syntax as a normal rsync-
 daemon transfer, with the only exception being that you must explicitly
 set the remote shell program on the command-line with the --rsh=COMMAND
 option. (Setting the RSYNC_RSH in the environment will not turn on this
 functionality.) For example:
 rsync -av --rsh=ssh host::module /dest
 If you need to specify a different remote-shell user, keep in mind that
 the user@ prefix in front of the host is specifying the rsync-user
 value (for a module that requires user-based authentication). This
 means that you must give the '-l user' option to ssh when specifying
 the remote-shell, as in this example that uses the short version of the
 --rsh option:
 rsync -av -e "ssh -l ssh-user" rsync-user@host::module /dest
 The "ssh-user" will be used at the ssh level; the "rsync-user" will be
 used to log-in to the "module".
 In this setup, the daemon is started by the ssh command that is
 accessing the system (which can be forced via the
 ~/.ssh/authorized_keys file, if desired). However, when accessing a
 daemon directly, it needs to be started beforehand.

STARTING AN RSYNC DAEMON TO ACCEPT CONNECTIONS

 In order to connect to an rsync daemon, the remote system needs to have
 a daemon already running (or it needs to have configured something like
 inetd to spawn an rsync daemon for incoming connections on a particular
 port). For full information on how to start a daemon that will
 handling incoming socket connections, see the rsyncd.conf(5)  manpage --
 that is the config file for the daemon, and it contains the full
 details for how to run the daemon (including stand-alone and inetd
 configurations).
 If you're using one of the remote-shell transports for the transfer,
 there is no need to manually start an rsync daemon.

EXAMPLES

 Here are some examples of how rsync can be used.
 To backup a home directory, which consists of large MS Word files and
 mail folders, a per-user cron job can be used that runs this each day:
 rsync -aiz . bkhost:backup/joe/
 To move some files from a remote host to the local host, you could run:
 rsync -aiv --remove-source-files rhost:/tmp/{file1,file2}.c ~/src/

OPTION SUMMARY

 Here is a short summary of the options available in rsync. Each option
 also has its own detailed description later in this manpage.
 --verbose, -v increase verbosity
 --info=FLAGS fine-grained informational verbosity
 --debug=FLAGS fine-grained debug verbosity
 --stderr=e|a|c change stderr output mode (default: errors)
 --quiet, -q suppress non-error messages
 --no-motd suppress daemon-mode MOTD
 --checksum, -c skip based on checksum, not mod-time & size
 --archive, -a archive mode is -rlptgoD (no -A,-X,-U,-N,-H)
 --no-OPTION turn off an implied OPTION (e.g. --no-D)
 --recursive, -r recurse into directories
 --relative, -R use relative path names
 --no-implied-dirs don't send implied dirs with --relative
 --backup, -b make backups (see --suffix & --backup-dir)
 --backup-dir=DIR make backups into hierarchy based in DIR
 --suffix=SUFFIX backup suffix (default ~ w/o --backup-dir)
 --update, -u skip files that are newer on the receiver
 --inplace update destination files in-place
 --append append data onto shorter files
 --append-verify --append w/old data in file checksum
 --dirs, -d transfer directories without recursing
 --old-dirs, --old-d works like --dirs when talking to old rsync
 --mkpath create destination's missing path components
 --links, -l copy symlinks as symlinks
 --copy-links, -L transform symlink into referent file/dir
 --copy-unsafe-links only "unsafe" symlinks are transformed
 --safe-links ignore symlinks that point outside the tree
 --munge-links munge symlinks to make them safe & unusable
 --copy-dirlinks, -k transform symlink to dir into referent dir
 --keep-dirlinks, -K treat symlinked dir on receiver as dir
 --hard-links, -H preserve hard links
 --perms, -p preserve permissions
 --fileflags preserve file-flags (aka chflags)
 --executability, -E preserve executability
 --chmod=CHMOD affect file and/or directory permissions
 --acls, -A preserve ACLs (implies --perms)
 --xattrs, -X preserve extended attributes
 --owner, -o preserve owner (super-user only)
 --group, -g preserve group
 --devices preserve device files (super-user only)
 --copy-devices copy device contents as a regular file
 --write-devices write to devices as files (implies --inplace)
 --specials preserve special files
 -D same as --devices --specials
 --times, -t preserve modification times
 --atimes, -U preserve access (use) times
 --open-noatime avoid changing the atime on opened files
 --crtimes, -N preserve create times (newness)
 --omit-dir-times, -O omit directories from --times
 --omit-link-times, -J omit symlinks from --times
 --super receiver attempts super-user activities
 --fake-super store/recover privileged attrs using xattrs
 --sparse, -S turn sequences of nulls into sparse blocks
 --preallocate allocate dest files before writing them
 --dry-run, -n perform a trial run with no changes made
 --whole-file, -W copy files whole (w/o delta-xfer algorithm)
 --checksum-choice=STR choose the checksum algorithm (aka --cc)
 --one-file-system, -x don't cross filesystem boundaries
 --block-size=SIZE, -B force a fixed checksum block-size
 --rsh=COMMAND, -e specify the remote shell to use
 --rsync-path=PROGRAM specify the rsync to run on remote machine
 --existing skip creating new files on receiver
 --ignore-existing skip updating files that exist on receiver
 --remove-source-files sender removes synchronized files (non-dir)
 --del an alias for --delete-during
 --delete delete extraneous files from dest dirs
 --delete-before receiver deletes before xfer, not during
 --delete-during receiver deletes during the transfer
 --delete-delay find deletions during, delete after
 --delete-after receiver deletes after transfer, not during
 --delete-excluded also delete excluded files from dest dirs
 --ignore-missing-args ignore missing source args without error
 --delete-missing-args delete missing source args from destination
 --ignore-errors delete even if there are I/O errors
 --force-delete force deletion of directories even if not empty
 --force-change affect user-/system-immutable files/dirs
 --force-uchange affect user-immutable files/dirs
 --force-schange affect system-immutable files/dirs
 --max-delete=NUM don't delete more than NUM files
 --max-size=SIZE don't transfer any file larger than SIZE
 --min-size=SIZE don't transfer any file smaller than SIZE
 --max-alloc=SIZE change a limit relating to memory alloc
 --partial keep partially transferred files
 --partial-dir=DIR put a partially transferred file into DIR
 --delay-updates put all updated files into place at end
 --prune-empty-dirs, -m prune empty directory chains from file-list
 --numeric-ids don't map uid/gid values by user/group name
 --usermap=STRING custom username mapping
 --groupmap=STRING custom groupname mapping
 --chown=USER:GROUP simple username/groupname mapping
 --timeout=SECONDS set I/O timeout in seconds
 --contimeout=SECONDS set daemon connection timeout in seconds
 --ignore-times, -I don't skip files that match size and time
 --size-only skip files that match in size
 --modify-window=NUM, -@ set the accuracy for mod-time comparisons
 --temp-dir=DIR, -T create temporary files in directory DIR
 --fuzzy, -y find similar file for basis if no dest file
 --compare-dest=DIR also compare destination files relative to DIR
 --copy-dest=DIR ... and include copies of unchanged files
 --link-dest=DIR hardlink to files in DIR when unchanged
 --compress, -z compress file data during the transfer
 --compress-choice=STR choose the compression algorithm (aka --zc)
 --compress-level=NUM explicitly set compression level (aka --zl)
 --skip-compress=LIST skip compressing files with suffix in LIST
 --cvs-exclude, -C auto-ignore files in the same way CVS does
 --filter=RULE, -f add a file-filtering RULE
 -F same as --filter='dir-merge /.rsync-filter'
 repeated: --filter='- .rsync-filter'
 --exclude=PATTERN exclude files matching PATTERN
 --exclude-from=FILE read exclude patterns from FILE
 --include=PATTERN don't exclude files matching PATTERN
 --include-from=FILE read include patterns from FILE
 --files-from=FILE read list of source-file names from FILE
 --from0, -0 all *-from/filter files are delimited by 0s
 --old-args disable the modern arg-protection idiom
 --secluded-args, -s use the protocol to safely send the args
 --trust-sender trust the remote sender's file list
 --copy-as=USER[:GROUP] specify user & optional group for the copy
 --address=ADDRESS bind address for outgoing socket to daemon
 --port=PORT specify double-colon alternate port number
 --sockopts=OPTIONS specify custom TCP options
 --blocking-io use blocking I/O for the remote shell
 --outbuf=N|L|B set out buffering to None, Line, or Block
 --stats give some file-transfer stats
 --8-bit-output, -8 leave high-bit chars unescaped in output
 --human-readable, -h output numbers in a human-readable format
 --progress show progress during transfer
 -P same as --partial --progress
 --itemize-changes, -i output a change-summary for all updates
 --remote-option=OPT, -M send OPTION to the remote side only
 --out-format=FORMAT output updates using the specified FORMAT
 --log-file=FILE log what we're doing to the specified FILE
 --log-file-format=FMT log updates using the specified FMT
 --password-file=FILE read daemon-access password from FILE
 --early-input=FILE use FILE for daemon's early exec input
 --list-only list the files instead of copying them
 --bwlimit=RATE limit socket I/O bandwidth
 --stop-after=MINS Stop rsync after MINS minutes have elapsed
 --stop-at=y-m-dTh:m Stop rsync at the specified point in time
 --fsync fsync every written file
 --write-batch=FILE write a batched update to FILE
 --only-write-batch=FILE like --write-batch but w/o updating dest
 --read-batch=FILE read a batched update from FILE
 --protocol=NUM force an older protocol version to be used
 --iconv=CONVERT_SPEC request charset conversion of filenames
 --checksum-seed=NUM set block/file checksum seed (advanced)
 --ipv4, -4 prefer IPv4
 --ipv6, -6 prefer IPv6
 --version, -V print the version + other info and exit
 --help, -h (*) show this help (* -h is help only on its own)
 Rsync can also be run as a daemon, in which case the following options
 are accepted:
 --daemon run as an rsync daemon
 --address=ADDRESS bind to the specified address
 --bwlimit=RATE limit socket I/O bandwidth
 --config=FILE specify alternate rsyncd.conf file
 --dparam=OVERRIDE, -M override global daemon config parameter
 --no-detach do not detach from the parent
 --port=PORT listen on alternate port number
 --log-file=FILE override the "log file" setting
 --log-file-format=FMT override the "log format" setting
 --sockopts=OPTIONS specify custom TCP options
 --verbose, -v increase verbosity
 --ipv4, -4 prefer IPv4
 --ipv6, -6 prefer IPv6
 --help, -h show this help (when used with --daemon)

OPTIONS

 Rsync accepts both long (double-dash + word) and short (single-dash +
 letter) options. The full list of the available options are described
 below. If an option can be specified in more than one way, the choices
 are comma-separated. Some options only have a long variant, not a
 short.
 If the option takes a parameter, the parameter is only listed after the
 long variant, even though it must also be specified for the short.
 When specifying a parameter, you can either use the form
 --option=param, --option param, -o=param, -o param, or -oparam (the
 latter choices assume that your option has a short variant).
 The parameter may need to be quoted in some manner for it to survive
 the shell's command-line parsing. Also keep in mind that a leading
 tilde (~) in a pathname is substituted by your shell, so make sure that
 you separate the option name from the pathname using a space if you
 want the local shell to expand it.
 --help Print a short help page describing the options available in
 rsync and exit. You can also use -h for --help when it is used
 without any other options (since it normally means --human-
 readable).
 --version, -V
 Print the rsync version plus other info and exit. When
 repeated, the information is output is a JSON format that is
 still fairly readable (client side only).
 The output includes a list of compiled-in capabilities, a list
 of optimizations, the default list of checksum algorithms, the
 default list of compression algorithms, the default list of
 daemon auth digests, a link to the rsync web site, and a few
 other items.
 --verbose, -v
 This option increases the amount of information you are given
 during the transfer. By default, rsync works silently. A
 single -v will give you information about what files are being
 transferred and a brief summary at the end. Two -v options will
 give you information on what files are being skipped and
 slightly more information at the end. More than two -v options
 should only be used if you are debugging rsync.
 The end-of-run summary tells you the number of bytes sent to the
 remote rsync (which is the receiving side on a local copy), the
 number of bytes received from the remote host, and the average
 bytes per second of the transferred data computed over the
 entire length of the rsync run. The second line shows the total
 size (in bytes), which is the sum of all the file sizes that
 rsync considered transferring. It also shows a "speedup" value,
 which is a ratio of the total file size divided by the sum of
 the sent and received bytes (which is really just a feel-good
 bigger-is-better number). Note that these byte values can be
 made more (or less) human-readable by using the --human-readable
 (or --no-human-readable) options.
 In a modern rsync, the -v option is equivalent to the setting of
 groups of --info and --debug options. You can choose to use
 these newer options in addition to, or in place of using
 --verbose, as any fine-grained settings override the implied
 settings of -v. Both --info and --debug have a way to ask for
 help that tells you exactly what flags are set for each increase
 in verbosity.
 However, do keep in mind that a daemon's "max verbosity" setting
 will limit how high of a level the various individual flags can
 be set on the daemon side. For instance, if the max is 2, then
 any info and/or debug flag that is set to a higher value than
 what would be set by -vv will be downgraded to the -vv level in
 the daemon's logging.
 --info=FLAGS
 This option lets you have fine-grained control over the
 information output you want to see. An individual flag name may
 be followed by a level number, with 0 meaning to silence that
 output, 1 being the default output level, and higher numbers
 increasing the output of that flag (for those that support
 higher levels). Use --info=help to see all the available flag
 names, what they output, and what flag names are added for each
 increase in the verbose level. Some examples:
 rsync -a --info=progress2 src/ dest/
 rsync -avv --info=stats2,misc1,flist0 src/ dest/
 Note that --info=name's output is affected by the --out-format
 and --itemize-changes (-i) options. See those options for more
 information on what is output and when.
 This option was added to 3.1.0, so an older rsync on the server
 side might reject your attempts at fine-grained control (if one
 or more flags needed to be send to the server and the server was
 too old to understand them). See also the "max verbosity"
 caveat above when dealing with a daemon.
 --debug=FLAGS
 This option lets you have fine-grained control over the debug
 output you want to see. An individual flag name may be followed
 by a level number, with 0 meaning to silence that output, 1
 being the default output level, and higher numbers increasing
 the output of that flag (for those that support higher levels).
 Use --debug=help to see all the available flag names, what they
 output, and what flag names are added for each increase in the
 verbose level. Some examples:
 rsync -avvv --debug=none src/ dest/
 rsync -avA --del --debug=del2,acl src/ dest/
 Note that some debug messages will only be output when the
 --stderr=all option is specified, especially those pertaining to
 I/O and buffer debugging.
 Beginning in 3.2.0, this option is no longer auto-forwarded to
 the server side in order to allow you to specify different debug
 values for each side of the transfer, as well as to specify a
 new debug option that is only present in one of the rsync
 versions. If you want to duplicate the same option on both
 sides, using brace expansion is an easy way to save you some
 typing. This works in zsh and bash:
 rsync -aiv {-M,}--debug=del2 src/ dest/
 --stderr=errors|all|client
 This option controls which processes output to stderr and if
 info messages are also changed to stderr. The mode strings can
 be abbreviated, so feel free to use a single letter value. The
 3 possible choices are:
 o errors - (the default) causes all the rsync processes to
 send an error directly to stderr, even if the process is
 on the remote side of the transfer. Info messages are
 sent to the client side via the protocol stream. If
 stderr is not available (i.e. when directly connecting
 with a daemon via a socket) errors fall back to being
 sent via the protocol stream.
 o all - causes all rsync messages (info and error) to get
 written directly to stderr from all (possible) processes.
 This causes stderr to become line-buffered (instead of
 raw) and eliminates the ability to divide up the info and
 error messages by file handle. For those doing debugging
 or using several levels of verbosity, this option can
 help to avoid clogging up the transfer stream (which
 should prevent any chance of a deadlock bug hanging
 things up). It also allows --debug to enable some extra
 I/O related messages.
 o client - causes all rsync messages to be sent to the
 client side via the protocol stream. One client process
 outputs all messages, with errors on stderr and info
 messages on stdout. This was the default in older rsync
 versions, but can cause error delays when a lot of
 transfer data is ahead of the messages. If you're
 pushing files to an older rsync, you may want to use
 --stderr=all since that idiom has been around for several
 releases.
 This option was added in rsync 3.2.3. This version also began
 the forwarding of a non-default setting to the remote side,
 though rsync uses the backward-compatible options --msgs2stderr
 and --no-msgs2stderr to represent the all and client settings,
 respectively. A newer rsync will continue to accept these older
 option names to maintain compatibility.
 --quiet, -q
 This option decreases the amount of information you are given
 during the transfer, notably suppressing information messages
 from the remote server. This option is useful when invoking
 rsync from cron.
 --no-motd
 This option affects the information that is output by the client
 at the start of a daemon transfer. This suppresses the message-
 of-the-day (MOTD) text, but it also affects the list of modules
 that the daemon sends in response to the "rsync host::" request
 (due to a limitation in the rsync protocol), so omit this option
 if you want to request the list of modules from the daemon.
 --ignore-times, -I
 Normally rsync will skip any files that are already the same
 size and have the same modification timestamp. This option
 turns off this "quick check" behavior, causing all files to be
 updated.
 This option can be confusing compared to --ignore-existing and
 --ignore-non-existing in that that they cause rsync to transfer
 fewer files, while this option causes rsync to transfer more
 files.
 --size-only
 This modifies rsync's "quick check" algorithm for finding files
 that need to be transferred, changing it from the default of
 transferring files with either a changed size or a changed last-
 modified time to just looking for files that have changed in
 size. This is useful when starting to use rsync after using
 another mirroring system which may not preserve timestamps
 exactly.
 --modify-window=NUM, -@
 When comparing two timestamps, rsync treats the timestamps as
 being equal if they differ by no more than the modify-window
 value. The default is 0, which matches just integer seconds.
 If you specify a negative value (and the receiver is at least
 version 3.1.3) then nanoseconds will also be taken into account.
 Specifying 1 is useful for copies to/from MS Windows FAT
 filesystems, because FAT represents times with a 2-second
 resolution (allowing times to differ from the original by up to
 1 second).
 If you want all your transfers to default to comparing
 nanoseconds, you can create a ~/.popt file and put these lines
 in it:
 rsync alias -a -a@-1
 rsync alias -t -t@-1
 With that as the default, you'd need to specify --modify-
 window=0 (aka -@0) to override it and ignore nanoseconds, e.g.
 if you're copying between ext3 and ext4, or if the receiving
 rsync is older than 3.1.3.
 --checksum, -c
 This changes the way rsync checks if the files have been changed
 and are in need of a transfer. Without this option, rsync uses
 a "quick check" that (by default) checks if each file's size and
 time of last modification match between the sender and receiver.
 This option changes this to compare a 128-bit checksum for each
 file that has a matching size. Generating the checksums means
 that both sides will expend a lot of disk I/O reading all the
 data in the files in the transfer, so this can slow things down
 significantly (and this is prior to any reading that will be
 done to transfer changed files)
 The sending side generates its checksums while it is doing the
 file-system scan that builds the list of the available files.
 The receiver generates its checksums when it is scanning for
 changed files, and will checksum any file that has the same size
 as the corresponding sender's file: files with either a changed
 size or a changed checksum are selected for transfer.
 Note that rsync always verifies that each transferred file was
 correctly reconstructed on the receiving side by checking a
 whole-file checksum that is generated as the file is
 transferred, but that automatic after-the-transfer verification
 has nothing to do with this option's before-the-transfer "Does
 this file need to be updated?" check.
 The checksum used is auto-negotiated between the client and the
 server, but can be overridden using either the --checksum-choice
 (--cc) option or an environment variable that is discussed in
 that option's section.
 --archive, -a
 This is equivalent to -rlptgoD. It is a quick way of saying you
 want recursion and want to preserve almost everything. Be aware
 that it does not include preserving ACLs (-A), xattrs (-X),
 atimes (-U), crtimes (-N), nor the finding and preserving of
 hardlinks (-H). It also does not imply --fileflags.
 The only exception to the above equivalence is when --files-from
 is specified, in which case -r is not implied.
 --no-OPTION
 You may turn off one or more implied options by prefixing the
 option name with "no-". Not all positive options have a negated
 opposite, but a lot do, including those that can be used to
 disable an implied option (e.g. --no-D, --no-perms) or have
 different defaults in various circumstances (e.g. --no-whole-
 file, --no-blocking-io, --no-dirs). Every valid negated option
 accepts both the short and the long option name after the "no-"
 prefix (e.g. --no-R is the same as --no-relative).
 As an example, if you want to use --archive (-a) but don't want
 --owner (-o), instead of converting -a into -rlptgD, you can
 specify -a --no-o (aka --archive --no-owner).
 The order of the options is important: if you specify --no-r -a,
 the -r option would end up being turned on, the opposite of
 -a --no-r. Note also that the side-effects of the --files-from
 option are NOT positional, as it affects the default state of
 several options and slightly changes the meaning of -a (see the
 --files-from option for more details).
 --recursive, -r
 This tells rsync to copy directories recursively. See also
 --dirs (-d) for an option that allows the scanning of a single
 directory.
 See the --inc-recursive option for a discussion of the
 incremental recursion for creating the list of files to
 transfer.
 --inc-recursive, --i-r
 This option explicitly enables on incremental recursion when
 scanning for files, which is enabled by default when using the
 --recursive option and both sides of the transfer are running
 rsync 3.0.0 or newer.
 Incremental recursion uses much less memory than non-
 incremental, while also beginning the transfer more quickly
 (since it doesn't need to scan the entire transfer hierarchy
 before it starts transferring files). If no recursion is
 enabled in the source files, this option has no effect.
 Some options require rsync to know the full file list, so these
 options disable the incremental recursion mode. These include:
 o --delete-before (the old default of --delete)
 o --delete-after
 o --prune-empty-dirs
 o --delay-updates
 In order to make --delete compatible with incremental recursion,
 rsync 3.0.0 made --delete-during the default delete mode (which
 was first added in 2.6.4).
 One side-effect of incremental recursion is that any missing
 sub-directories inside a recursively-scanned directory are (by
 default) created prior to recursing into the sub-dirs. This
 earlier creation point (compared to a non-incremental recursion)
 allows rsync to then set the modify time of the finished
 directory right away (without having to delay that until a bunch
 of recursive copying has finished). However, these early
 directories don't yet have their completed mode, mtime, or
 ownership set -- they have more restrictive rights until the
 subdirectory's copying actually begins. This early-creation
 idiom can be avoided by using the --omit-dir-times option.
 Incremental recursion can be disabled using the --no-inc-
 recursive (--no-i-r) option.
 --no-inc-recursive, --no-i-r
 Disables the new incremental recursion algorithm of the
 --recursive option. This makes rsync scan the full file list
 before it begins to transfer files. See --inc-recursive for
 more info.
 --relative, -R
 Use relative paths. This means that the full path names
 specified on the command line are sent to the server rather than
 just the last parts of the filenames. This is particularly
 useful when you want to send several different directories at
 the same time. For example, if you used this command:
 rsync -av /foo/bar/baz.c remote:/tmp/
 would create a file named baz.c in /tmp/ on the remote machine.
 If instead you used
 rsync -avR /foo/bar/baz.c remote:/tmp/
 then a file named /tmp/foo/bar/baz.c would be created on the
 remote machine, preserving its full path. These extra path
 elements are called "implied directories" (i.e. the "foo" and
 the "foo/bar" directories in the above example).
 Beginning with rsync 3.0.0, rsync always sends these implied
 directories as real directories in the file list, even if a path
 element is really a symlink on the sending side. This prevents
 some really unexpected behaviors when copying the full path of a
 file that you didn't realize had a symlink in its path. If you
 want to duplicate a server-side symlink, include both the
 symlink via its path, and referent directory via its real path.
 If you're dealing with an older rsync on the sending side, you
 may need to use the --no-implied-dirs option.
 It is also possible to limit the amount of path information that
 is sent as implied directories for each path you specify. With
 a modern rsync on the sending side (beginning with 2.6.7), you
 can insert a dot and a slash into the source path, like this:
 rsync -avR /foo/./bar/baz.c remote:/tmp/
 That would create /tmp/bar/baz.c on the remote machine. (Note
 that the dot must be followed by a slash, so "/foo/." would not
 be abbreviated.) For older rsync versions, you would need to use
 a chdir to limit the source path. For example, when pushing
 files:
 (cd /foo; rsync -avR bar/baz.c remote:/tmp/)
 (Note that the parens put the two commands into a sub-shell, so
 that the "cd" command doesn't remain in effect for future
 commands.) If you're pulling files from an older rsync, use this
 idiom (but only for a non-daemon transfer):
 rsync -avR --rsync-path="cd /foo; rsync" \
 remote:bar/baz.c /tmp/
 --no-implied-dirs
 This option affects the default behavior of the --relative
 option. When it is specified, the attributes of the implied
 directories from the source names are not included in the
 transfer. This means that the corresponding path elements on
 the destination system are left unchanged if they exist, and any
 missing implied directories are created with default attributes.
 This even allows these implied path elements to have big
 differences, such as being a symlink to a directory on the
 receiving side.
 For instance, if a command-line arg or a files-from entry told
 rsync to transfer the file "path/foo/file", the directories
 "path" and "path/foo" are implied when --relative is used. If
 "path/foo" is a symlink to "bar" on the destination system, the
 receiving rsync would ordinarily delete "path/foo", recreate it
 as a directory, and receive the file into the new directory.
 With --no-implied-dirs, the receiving rsync updates
 "path/foo/file" using the existing path elements, which means
 that the file ends up being created in "path/bar". Another way
 to accomplish this link preservation is to use the --keep-
 dirlinks option (which will also affect symlinks to directories
 in the rest of the transfer).
 When pulling files from an rsync older than 3.0.0, you may need
 to use this option if the sending side has a symlink in the path
 you request and you wish the implied directories to be
 transferred as normal directories.
 --backup, -b
 With this option, preexisting destination files are renamed as
 each file is transferred or deleted. You can control where the
 backup file goes and what (if any) suffix gets appended using
 the --backup-dir and --suffix options.
 If you don't specify --backup-dir:
 1. the --omit-dir-times option will be forced on
 2. the use of --delete (without --delete-excluded), causes
 rsync to add a "protect" filter-rule for the backup
 suffix to the end of all your existing filters that looks
 like this: -f "P *~". This rule prevents previously
 backed-up files from being deleted.
 Note that if you are supplying your own filter rules, you may
 need to manually insert your own exclude/protect rule somewhere
 higher up in the list so that it has a high enough priority to
 be effective (e.g. if your rules specify a trailing
 inclusion/exclusion of *, the auto-added rule would never be
 reached).
 --backup-dir=DIR
 This implies the --backup option, and tells rsync to store all
 backups in the specified directory on the receiving side. This
 can be used for incremental backups. You can additionally
 specify a backup suffix using the --suffix option (otherwise the
 files backed up in the specified directory will keep their
 original filenames).
 Note that if you specify a relative path, the backup directory
 will be relative to the destination directory, so you probably
 want to specify either an absolute path or a path that starts
 with "../". If an rsync daemon is the receiver, the backup dir
 cannot go outside the module's path hierarchy, so take extra
 care not to delete it or copy into it.
 --suffix=SUFFIX
 This option allows you to override the default backup suffix
 used with the --backup (-b) option. The default suffix is a ~
 if no --backup-dir was specified, otherwise it is an empty
 string.
 --update, -u
 This forces rsync to skip any files which exist on the
 destination and have a modified time that is newer than the
 source file. (If an existing destination file has a modification
 time equal to the source file's, it will be updated if the sizes
 are different.)
 Note that this does not affect the copying of dirs, symlinks, or
 other special files. Also, a difference of file format between
 the sender and receiver is always considered to be important
 enough for an update, no matter what date is on the objects. In
 other words, if the source has a directory where the destination
 has a file, the transfer would occur regardless of the
 timestamps.
 This option is a TRANSFER RULE, so don't expect any exclude side
 effects.
 A caution for those that choose to combine --inplace with
 --update: an interrupted transfer will leave behind a partial
 file on the receiving side that has a very recent modified time,
 so re-running the transfer will probably not continue the
 interrupted file. As such, it is usually best to avoid
 combining this with --inplace unless you have implemented manual
 steps to handle any interrupted in-progress files.
 --inplace
 This option changes how rsync transfers a file when its data
 needs to be updated: instead of the default method of creating a
 new copy of the file and moving it into place when it is
 complete, rsync instead writes the updated data directly to the
 destination file.
 This has several effects:
 o Hard links are not broken. This means the new data will
 be visible through other hard links to the destination
 file. Moreover, attempts to copy differing source files
 onto a multiply-linked destination file will result in a
 "tug of war" with the destination data changing back and
 forth.
 o In-use binaries cannot be updated (either the OS will
 prevent this from happening, or binaries that attempt to
 swap-in their data will misbehave or crash).
 o The file's data will be in an inconsistent state during
 the transfer and will be left that way if the transfer is
 interrupted or if an update fails.
 o A file that rsync cannot write to cannot be updated.
 While a super user can update any file, a normal user
 needs to be granted write permission for the open of the
 file for writing to be successful.
 o The efficiency of rsync's delta-transfer algorithm may be
 reduced if some data in the destination file is
 overwritten before it can be copied to a position later
 in the file. This does not apply if you use --backup,
 since rsync is smart enough to use the backup file as the
 basis file for the transfer.
 WARNING: you should not use this option to update files that are
 being accessed by others, so be careful when choosing to use
 this for a copy.
 This option is useful for transferring large files with block-
 based changes or appended data, and also on systems that are
 disk bound, not network bound. It can also help keep a copy-on-
 write filesystem snapshot from diverging the entire contents of
 a file that only has minor changes.
 The option implies --partial (since an interrupted transfer does
 not delete the file), but conflicts with --partial-dir and
 --delay-updates. Prior to rsync 2.6.4 --inplace was also
 incompatible with --compare-dest and --link-dest.
 --append
 This special copy mode only works to efficiently update files
 that are known to be growing larger where any existing content
 on the receiving side is also known to be the same as the
 content on the sender. The use of --append can be dangerous if
 you aren't 100% sure that all the files in the transfer are
 shared, growing files. You should thus use filter rules to
 ensure that you weed out any files that do not fit this
 criteria.
 Rsync updates these growing file in-place without verifying any
 of the existing content in the file (it only verifies the
 content that it is appending). Rsync skips any files that exist
 on the receiving side that are not shorter than the associated
 file on the sending side (which means that new files are
 transferred). It also skips any files whose size on the sending
 side gets shorter during the send negotiations (rsync warns
 about a "diminished" file when this happens).
 This does not interfere with the updating of a file's non-
 content attributes (e.g. permissions, ownership, etc.) when the
 file does not need to be transferred, nor does it affect the
 updating of any directories or non-regular files.
 --append-verify
 This special copy mode works like --append except that all the
 data in the file is included in the checksum verification
 (making it less efficient but also potentially safer). This
 option can be dangerous if you aren't 100% sure that all the
 files in the transfer are shared, growing files. See the
 --append option for more details.
 Note: prior to rsync 3.0.0, the --append option worked like
 --append-verify, so if you are interacting with an older rsync
 (or the transfer is using a protocol prior to 30), specifying
 either append option will initiate an --append-verify transfer.
 --dirs, -d
 Tell the sending side to include any directories that are
 encountered. Unlike --recursive, a directory's contents are not
 copied unless the directory name specified is "." or ends with a
 trailing slash (e.g. ".", "dir/.", "dir/", etc.). Without this
 option or the --recursive option, rsync will skip all
 directories it encounters (and output a message to that effect
 for each one). If you specify both --dirs and --recursive,
 --recursive takes precedence.
 The --dirs option is implied by the --files-from option or the
 --list-only option (including an implied --list-only usage) if
 --recursive wasn't specified (so that directories are seen in
 the listing). Specify --no-dirs (or --no-d) if you want to turn
 this off.
 There is also a backward-compatibility helper option, --old-dirs
 (--old-d) that tells rsync to use a hack of -r --exclude='/*/*'
 to get an older rsync to list a single directory without
 recursing.
 --mkpath
 Create all missing path components of the destination path.
 By default, rsync allows only the final component of the
 destination path to not exist, which is an attempt to help you
 to validate your destination path. With this option, rsync
 creates all the missing destination-path components, just as if
 mkdir -p $DEST_PATH had been run on the receiving side.
 When specifying a destination path, including a trailing slash
 ensures that the whole path is treated as directory names to be
 created, even when the file list has a single item. See the
 COPYING TO A DIFFERENT NAME section for full details on how
 rsync decides if a final destination-path component should be
 created as a directory or not.
 If you would like the newly-created destination dirs to match
 the dirs on the sending side, you should be using --relative
 (-R) instead of --mkpath. For instance, the following two
 commands result in the same destination tree, but only the
 second command ensures that the "some/extra/path" components
 match the dirs on the sending side:
 rsync -ai --mkpath host:some/extra/path/*.c some/extra/path/
 rsync -aiR host:some/extra/path/*.c ./
 --links, -l
 Add symlinks to the transferred files instead of noisily
 ignoring them with a "non-regular file" warning for each symlink
 encountered. You can alternately silence the warning by
 specifying --info=nonreg0.
 The default handling of symlinks is to recreate each symlink's
 unchanged value on the receiving side.
 See the SYMBOLIC LINKS section for multi-option info.
 --copy-links, -L
 The sender transforms each symlink encountered in the transfer
 into the referent item, following the symlink chain to the file
 or directory that it references. If a symlink chain is broken,
 an error is output and the file is dropped from the transfer.
 This option supersedes any other options that affect symlinks in
 the transfer, since there are no symlinks left in the transfer.
 This option does not change the handling of existing symlinks on
 the receiving side, unlike versions of rsync prior to 2.6.3
 which had the side-effect of telling the receiving side to also
 follow symlinks. A modern rsync won't forward this option to a
 remote receiver (since only the sender needs to know about it),
 so this caveat should only affect someone using an rsync client
 older than 2.6.7 (which is when -L stopped being forwarded to
 the receiver).
 See the --keep-dirlinks (-K) if you need a symlink to a
 directory to be treated as a real directory on the receiving
 side.
 See the SYMBOLIC LINKS section for multi-option info.
 --copy-unsafe-links
 This tells rsync to copy the referent of symbolic links that
 point outside the copied tree. Absolute symlinks are also
 treated like ordinary files, and so are any symlinks in the
 source path itself when --relative is used.
 Note that the cut-off point is the top of the transfer, which is
 the part of the path that rsync isn't mentioning in the verbose
 output. If you copy "/src/subdir" to "/dest/" then the "subdir"
 directory is a name inside the transfer tree, not the top of the
 transfer (which is /src) so it is legal for created relative
 symlinks to refer to other names inside the /src and /dest
 directories. If you instead copy "/src/subdir/" (with a
 trailing slash) to "/dest/subdir" that would not allow symlinks
 to any files outside of "subdir".
 Note that safe symlinks are only copied if --links was also
 specified or implied. The --copy-unsafe-links option has no
 extra effect when combined with --copy-links.
 See the SYMBOLIC LINKS section for multi-option info.
 --safe-links
 This tells the receiving rsync to ignore any symbolic links in
 the transfer which point outside the copied tree. All absolute
 symlinks are also ignored.
 Since this ignoring is happening on the receiving side, it will
 still be effective even when the sending side has munged
 symlinks (when it is using --munge-links). It also affects
 deletions, since the file being present in the transfer prevents
 any matching file on the receiver from being deleted when the
 symlink is deemed to be unsafe and is skipped.
 This option must be combined with --links (or --archive) to have
 any symlinks in the transfer to conditionally ignore. Its effect
 is superseded by --copy-unsafe-links.
 Using this option in conjunction with --relative may give
 unexpected results.
 See the SYMBOLIC LINKS section for multi-option info.
 --munge-links
 This option affects just one side of the transfer and tells
 rsync to munge symlink values when it is receiving files or
 unmunge symlink values when it is sending files. The munged
 values make the symlinks unusable on disk but allows the
 original contents of the symlinks to be recovered.
 The server-side rsync often enables this option without the
 client's knowledge, such as in an rsync daemon's configuration
 file or by an option given to the rrsync (restricted rsync)
 script. When specified on the client side, specify the option
 normally if it is the client side that has/needs the munged
 symlinks, or use -M--munge-links to give the option to the
 server when it has/needs the munged symlinks. Note that on a
 local transfer, the client is the sender, so specifying the
 option directly unmunges symlinks while specifying it as a
 remote option munges symlinks.
 This option has no effect when sent to a daemon via --remote-
 option because the daemon configures whether it wants munged
 symlinks via its "munge symlinks" parameter.
 The symlink value is munged/unmunged once it is in the transfer,
 so any option that transforms symlinks into non-symlinks occurs
 prior to the munging/unmunging except for --safe-links, which is
 a choice that the receiver makes, so it bases its decision on
 the munged/unmunged value. This does mean that if a receiver
 has munging enabled, that using --safe-links will cause all
 symlinks to be ignored (since they are all absolute).
 The method that rsync uses to munge the symlinks is to prefix
 each one's value with the string "/rsyncd-munged/". This
 prevents the links from being used as long as the directory does
 not exist. When this option is enabled, rsync will refuse to
 run if that path is a directory or a symlink to a directory
 (though it only checks at startup). See also the "munge-
 symlinks" python script in the support directory of the source
 code for a way to munge/unmunge one or more symlinks in-place.
 --copy-dirlinks, -k
 This option causes the sending side to treat a symlink to a
 directory as though it were a real directory. This is useful if
 you don't want symlinks to non-directories to be affected, as
 they would be using --copy-links.
 Without this option, if the sending side has replaced a
 directory with a symlink to a directory, the receiving side will
 delete anything that is in the way of the new symlink, including
 a directory hierarchy (as long as --force-delete or --delete is
 in effect).
 See also --keep-dirlinks for an analogous option for the
 receiving side.
 --copy-dirlinks applies to all symlinks to directories in the
 source. If you want to follow only a few specified symlinks, a
 trick you can use is to pass them as additional source args with
 a trailing slash, using --relative to make the paths match up
 right. For example:
 rsync -r --relative src/./ src/./follow-me/ dest/
 This works because rsync calls lstat(2)  on the source arg as
 given, and the trailing slash makes lstat(2)  follow the symlink,
 giving rise to a directory in the file-list which overrides the
 symlink found during the scan of "src/./".
 See the SYMBOLIC LINKS section for multi-option info.
 --keep-dirlinks, -K
 This option causes the receiving side to treat a symlink to a
 directory as though it were a real directory, but only if it
 matches a real directory from the sender. Without this option,
 the receiver's symlink would be deleted and replaced with a real
 directory.
 For example, suppose you transfer a directory "foo" that
 contains a file "file", but "foo" is a symlink to directory
 "bar" on the receiver. Without --keep-dirlinks, the receiver
 deletes symlink "foo", recreates it as a directory, and receives
 the file into the new directory. With --keep-dirlinks, the
 receiver keeps the symlink and "file" ends up in "bar".
 One note of caution: if you use --keep-dirlinks, you must trust
 all the symlinks in the copy or enable the --munge-links option
 on the receiving side! If it is possible for an untrusted user
 to create their own symlink to any real directory, the user
 could then (on a subsequent copy) replace the symlink with a
 real directory and affect the content of whatever directory the
 symlink references. For backup copies, you are better off using
 something like a bind mount instead of a symlink to modify your
 receiving hierarchy.
 See also --copy-dirlinks for an analogous option for the sending
 side.
 See the SYMBOLIC LINKS section for multi-option info.
 --hard-links, -H
 This tells rsync to look for hard-linked files in the source and
 link together the corresponding files on the destination.
 Without this option, hard-linked files in the source are treated
 as though they were separate files.
 This option does NOT necessarily ensure that the pattern of hard
 links on the destination exactly matches that on the source.
 Cases in which the destination may end up with extra hard links
 include the following:
 o If the destination contains extraneous hard-links (more
 linking than what is present in the source file list),
 the copying algorithm will not break them explicitly.
 However, if one or more of the paths have content
 differences, the normal file-update process will break
 those extra links (unless you are using the --inplace
 option).
 o If you specify a --link-dest directory that contains hard
 links, the linking of the destination files against the
 --link-dest files can cause some paths in the destination
 to become linked together due to the --link-dest
 associations.
 Note that rsync can only detect hard links between files that
 are inside the transfer set. If rsync updates a file that has
 extra hard-link connections to files outside the transfer, that
 linkage will be broken. If you are tempted to use the --inplace
 option to avoid this breakage, be very careful that you know how
 your files are being updated so that you are certain that no
 unintended changes happen due to lingering hard links (and see
 the --inplace option for more caveats).
 If incremental recursion is active (see --inc-recursive), rsync
 may transfer a missing hard-linked file before it finds that
 another link for that contents exists elsewhere in the
 hierarchy. This does not affect the accuracy of the transfer
 (i.e. which files are hard-linked together), just its efficiency
 (i.e. copying the data for a new, early copy of a hard-linked
 file that could have been found later in the transfer in another
 member of the hard-linked set of files). One way to avoid this
 inefficiency is to disable incremental recursion using the --no-
 inc-recursive option.
 --perms, -p
 This option causes the receiving rsync to set the destination
 permissions to be the same as the source permissions. (See also
 the --chmod option for a way to modify what rsync considers to
 be the source permissions.)
 When this option is off, permissions are set as follows:
 o Existing files (including updated files) retain their
 existing permissions, though the --executability option
 might change just the execute permission for the file.
 o New files get their "normal" permission bits set to the
 source file's permissions masked with the receiving
 directory's default permissions (either the receiving
 process's umask, or the permissions specified via the
 destination directory's default ACL), and their special
 permission bits disabled except in the case where a new
 directory inherits a setgid bit from its parent
 directory.
 Thus, when --perms and --executability are both disabled,
 rsync's behavior is the same as that of other file-copy
 utilities, such as cp(1)  and tar(1) .
 In summary: to give destination files (both old and new) the
 source permissions, use --perms. To give new files the
 destination-default permissions (while leaving existing files
 unchanged), make sure that the --perms option is off and use
 --chmod=ugo=rwX (which ensures that all non-masked bits get
 enabled). If you'd care to make this latter behavior easier to
 type, you could define a popt alias for it, such as putting this
 line in the file ~/.popt (the following defines the -Z option,
 and includes --no-g to use the default group of the destination
 dir):
 rsync alias -Z --no-p --no-g --chmod=ugo=rwX
 You could then use this new option in a command such as this
 one:
 rsync -avZ src/ dest/
 (Caveat: make sure that -a does not follow -Z, or it will re-
 enable the two --no-* options mentioned above.)
 The preservation of the destination's setgid bit on newly-
 created directories when --perms is off was added in rsync
 2.6.7. Older rsync versions erroneously preserved the three
 special permission bits for newly-created files when --perms was
 off, while overriding the destination's setgid bit setting on a
 newly-created directory. Default ACL observance was added to
 the ACL patch for rsync 2.6.7, so older (or non-ACL-enabled)
 rsyncs use the umask even if default ACLs are present. (Keep in
 mind that it is the version of the receiving rsync that affects
 these behaviors.)
 --executability, -E
 This option causes rsync to preserve the executability (or non-
 executability) of regular files when --perms is not enabled. A
 regular file is considered to be executable if at least one 'x'
 is turned on in its permissions. When an existing destination
 file's executability differs from that of the corresponding
 source file, rsync modifies the destination file's permissions
 as follows:
 o To make a file non-executable, rsync turns off all its
 'x' permissions.
 o To make a file executable, rsync turns on each 'x'
 permission that has a corresponding 'r' permission
 enabled.
 If --perms is enabled, this option is ignored.
 --acls, -A
 This option causes rsync to update the destination ACLs to be
 the same as the source ACLs. The option also implies --perms.
 The source and destination systems must have compatible ACL
 entries for this option to work properly. See the --fake-super
 option for a way to backup and restore ACLs that are not
 compatible.
 --xattrs, -X
 This option causes rsync to update the destination extended
 attributes to be the same as the source ones.
 For systems that support extended-attribute namespaces, a copy
 being done by a super-user copies all namespaces except
 system.*. A normal user only copies the user.* namespace. To
 be able to backup and restore non-user namespaces as a normal
 user, see the --fake-super option.
 The above name filtering can be overridden by using one or more
 filter options with the x modifier. When you specify an xattr-
 affecting filter rule, rsync requires that you do your own
 system/user filtering, as well as any additional filtering for
 what xattr names are copied and what names are allowed to be
 deleted. For example, to skip the system namespace, you could
 specify:
 --filter='-x system.*'
 To skip all namespaces except the user namespace, you could
 specify a negated-user match:
 --filter='-x! user.*'
 To prevent any attributes from being deleted, you could specify
 a receiver-only rule that excludes all names:
 --filter='-xr *'
 Note that the -X option does not copy rsync's special xattr
 values (e.g. those used by --fake-super) unless you repeat the
 option (e.g. -XX). This "copy all xattrs" mode cannot be used
 with --fake-super.
 --fileflags
 This option causes rsync to update the file-flags to be the same
 as the source files and directories (if your OS supports the
 chflags(2)  system call). Some flags can only be altered by the
 super-user and some might only be unset below a certain secure-
 level (usually single-user mode). It will not make files
 alterable that are set to immutable on the receiver. To do
 that, see --force-change, --force-uchange, and --force-schange.
 --force-change
 This option causes rsync to disable both user-immutable and
 system-immutable flags on files and directories that are being
 updated or deleted on the receiving side. This option overrides
 --force-uchange and --force-schange.
 --force-uchange
 This option causes rsync to disable user-immutable flags on
 files and directories that are being updated or deleted on the
 receiving side. It does not try to affect system flags. This
 option overrides --force-change and --force-schange.
 --force-schange
 This option causes rsync to disable system-immutable flags on
 files and directories that are being updated or deleted on the
 receiving side. It does not try to affect user flags. This
 option overrides --force-change and --force-uchange.
 --chmod=CHMOD
 This option tells rsync to apply one or more comma-separated
 "chmod" modes to the permission of the files in the transfer.
 The resulting value is treated as though it were the permissions
 that the sending side supplied for the file, which means that
 this option can seem to have no effect on existing files if
 --perms is not enabled.
 In addition to the normal parsing rules specified in the
 chmod(1)  manpage, you can specify an item that should only apply
 to a directory by prefixing it with a 'D', or specify an item
 that should only apply to a file by prefixing it with a 'F'.
 For example, the following will ensure that all directories get
 marked set-gid, that no files are other-writable, that both are
 user-writable and group-writable, and that both have consistent
 executability across all bits:
 --chmod=Dg+s,ug+w,Fo-w,+X
 Using octal mode numbers is also allowed:
 --chmod=D2775,F664
 It is also legal to specify multiple --chmod options, as each
 additional option is just appended to the list of changes to
 make.
 See the --perms and --executability options for how the
 resulting permission value can be applied to the files in the
 transfer.
 --owner, -o
 This option causes rsync to set the owner of the destination
 file to be the same as the source file, but only if the
 receiving rsync is being run as the super-user (see also the
 --super and --fake-super options). Without this option, the
 owner of new and/or transferred files are set to the invoking
 user on the receiving side.
 The preservation of ownership will associate matching names by
 default, but may fall back to using the ID number in some
 circumstances (see also the --numeric-ids option for a full
 discussion).
 --group, -g
 This option causes rsync to set the group of the destination
 file to be the same as the source file. If the receiving
 program is not running as the super-user (or if --no-super was
 specified), only groups that the invoking user on the receiving
 side is a member of will be preserved. Without this option, the
 group is set to the default group of the invoking user on the
 receiving side.
 The preservation of group information will associate matching
 names by default, but may fall back to using the ID number in
 some circumstances (see also the --numeric-ids option for a full
 discussion).
 --devices
 This option causes rsync to transfer character and block device
 files to the remote system to recreate these devices. If the
 receiving rsync is not being run as the super-user, rsync
 silently skips creating the device files (see also the --super
 and --fake-super options).
 By default, rsync generates a "non-regular file" warning for
 each device file encountered when this option is not set. You
 can silence the warning by specifying --info=nonreg0.
 --specials
 This option causes rsync to transfer special files, such as
 named sockets and fifos. If the receiving rsync is not being
 run as the super-user, rsync silently skips creating the special
 files (see also the --super and --fake-super options).
 By default, rsync generates a "non-regular file" warning for
 each special file encountered when this option is not set. You
 can silence the warning by specifying --info=nonreg0.
 -D The -D option is equivalent to "--devices --specials".
 --copy-devices
 This tells rsync to treat a device on the sending side as a
 regular file, allowing it to be copied to a normal destination
 file (or another device if --write-devices was also specified).
 This option is refused by default by an rsync daemon.
 --write-devices
 This tells rsync to treat a device on the receiving side as a
 regular file, allowing the writing of file data into a device.
 This option implies the --inplace option.
 Be careful using this, as you should know what devices are
 present on the receiving side of the transfer, especially when
 running rsync as root.
 This option is refused by default by an rsync daemon.
 --times, -t
 This tells rsync to transfer modification times along with the
 files and update them on the remote system. Note that if this
 option is not used, the optimization that excludes files that
 have not been modified cannot be effective; in other words, a
 missing -t (or -a) will cause the next transfer to behave as if
 it used --ignore-times (-I), causing all files to be updated
 (though rsync's delta-transfer algorithm will make the update
 fairly efficient if the files haven't actually changed, you're
 much better off using -t).
 A modern rsync that is using transfer protocol 30 or 31 conveys
 a modify time using up to 8-bytes. If rsync is forced to speak
 an older protocol (perhaps due to the remote rsync being older
 than 3.0.0) a modify time is conveyed using 4-bytes. Prior to
 3.2.7, these shorter values could convey a date range of
 13-Dec-1901 to 19-Jan-2038. Beginning with 3.2.7, these 4-byte
 values now convey a date range of 1-Jan-1970 to 7-Feb-2106. If
 you have files dated older than 1970, make sure your rsync
 executables are upgraded so that the full range of dates can be
 conveyed.
 --atimes, -U
 This tells rsync to set the access (use) times of the
 destination files to the same value as the source files.
 If repeated, it also sets the --open-noatime option, which can
 help you to make the sending and receiving systems have the same
 access times on the transferred files without needing to run
 rsync an extra time after a file is transferred.
 Note that some older rsync versions (prior to 3.2.0) may have
 been built with a pre-release --atimes patch that does not imply
 --open-noatime when this option is repeated.
 --open-noatime
 This tells rsync to open files with the O_NOATIME flag (on
 systems that support it) to avoid changing the access time of
 the files that are being transferred. If your OS does not
 support the O_NOATIME flag then rsync will silently ignore this
 option. Note also that some filesystems are mounted to avoid
 updating the atime on read access even without the O_NOATIME
 flag being set.
 --crtimes, -N,
 This tells rsync to set the create times (newness) of the
 destination files to the same value as the source files. Your OS
 & filesystem must support the setting of arbitrary creation
 (birth) times for this option to be supported.
 --omit-dir-times, -O
 This tells rsync to omit directories when it is preserving
 modification, access, and create times. If NFS is sharing the
 directories on the receiving side, it is a good idea to use -O.
 This option is inferred if you use --backup without --backup-
 dir.
 This option also has the side-effect of avoiding early creation
 of missing sub-directories when incremental recursion is
 enabled, as discussed in the --inc-recursive section.
 --omit-link-times, -J
 This tells rsync to omit symlinks when it is preserving
 modification, access, and create times.
 --super
 This tells the receiving side to attempt super-user activities
 even if the receiving rsync wasn't run by the super-user. These
 activities include: preserving users via the --owner option,
 preserving all groups (not just the current user's groups) via
 the --group option, and copying devices via the --devices
 option. This is useful for systems that allow such activities
 without being the super-user, and also for ensuring that you
 will get errors if the receiving side isn't being run as the
 super-user. To turn off super-user activities, the super-user
 can use --no-super.
 --fake-super
 When this option is enabled, rsync simulates super-user
 activities by saving/restoring the privileged attributes via
 special extended attributes that are attached to each file (as
 needed). This includes the file's owner and group (if it is not
 the default), the file's device info (device & special files are
 created as empty text files), and any permission bits that we
 won't allow to be set on the real file (e.g. the real file gets
 u-s,g-s,o-t for safety) or that would limit the owner's access
 (since the real super-user can always access/change a file, the
 files we create can always be accessed/changed by the creating
 user). This option also handles ACLs (if --acls was specified)
 and non-user extended attributes (if --xattrs was specified).
 This is a good way to backup data without using a super-user,
 and to store ACLs from incompatible systems.
 The --fake-super option only affects the side where the option
 is used. To affect the remote side of a remote-shell
 connection, use the --remote-option (-M) option:
 rsync -av -M--fake-super /src/ host:/dest/
 For a local copy, this option affects both the source and the
 destination. If you wish a local copy to enable this option
 just for the destination files, specify -M--fake-super. If you
 wish a local copy to enable this option just for the source
 files, combine --fake-super with -M--super.
 This option is overridden by both --super and --no-super.
 See also the fake super setting in the daemon's rsyncd.conf
 file.
 --sparse, -S
 Try to handle sparse files efficiently so they take up less
 space on the destination. If combined with --inplace the file
 created might not end up with sparse blocks with some
 combinations of kernel version and/or filesystem type. If
 --whole-file is in effect (e.g. for a local copy) then it will
 always work because rsync truncates the file prior to writing
 out the updated version.
 Note that versions of rsync older than 3.1.3 will reject the
 combination of --sparse and --inplace.
 --preallocate
 This tells the receiver to allocate each destination file to its
 eventual size before writing data to the file. Rsync will only
 use the real filesystem-level preallocation support provided by
 Linux's fallocate(2) system call or Cygwin's posix_fallocate(3),
 not the slow glibc implementation that writes a null byte into
 each block.
 Without this option, larger files may not be entirely contiguous
 on the filesystem, but with this option rsync will probably copy
 more slowly. If the destination is not an extent-supporting
 filesystem (such as ext4, xfs, NTFS, etc.), this option may have
 no positive effect at all.
 If combined with --sparse, the file will only have sparse blocks
 (as opposed to allocated sequences of null bytes) if the kernel
 version and filesystem type support creating holes in the
 allocated data.
 --dry-run, -n
 This makes rsync perform a trial run that doesn't make any
 changes (and produces mostly the same output as a real run). It
 is most commonly used in combination with the --verbose (-v)
 and/or --itemize-changes (-i) options to see what an rsync
 command is going to do before one actually runs it.
 The output of --itemize-changes is supposed to be exactly the
 same on a dry run and a subsequent real run (barring intentional
 trickery and system call failures); if it isn't, that's a bug.
 Other output should be mostly unchanged, but may differ in some
 areas. Notably, a dry run does not send the actual data for
 file transfers, so --progress has no effect, the "bytes sent",
 "bytes received", "literal data", and "matched data" statistics
 are too small, and the "speedup" value is equivalent to a run
 where no file transfers were needed.
 --whole-file, -W
 This option disables rsync's delta-transfer algorithm, which
 causes all transferred files to be sent whole. The transfer may
 be faster if this option is used when the bandwidth between the
 source and destination machines is higher than the bandwidth to
 disk (especially when the "disk" is actually a networked
 filesystem). This is the default when both the source and
 destination are specified as local paths, but only if no batch-
 writing option is in effect.
 --no-whole-file, --no-W
 Disable whole-file updating when it is enabled by default for a
 local transfer. This usually slows rsync down, but it can be
 useful if you are trying to minimize the writes to the
 destination file (if combined with --inplace) or for testing the
 checksum-based update algorithm.
 See also the --whole-file option.
 --checksum-choice=STR, --cc=STR
 This option overrides the checksum algorithms. If one algorithm
 name is specified, it is used for both the transfer checksums
 and (assuming --checksum is specified) the pre-transfer
 checksums. If two comma-separated names are supplied, the first
 name affects the transfer checksums, and the second name affects
 the pre-transfer checksums (-c).
 The checksum options that you may be able to use are:
 o auto (the default automatic choice)
 o xxh128
 o xxh3
 o xxh64 (aka xxhash)
 o md5
 o md4
 o sha1
 o none
 Run rsync --version to see the default checksum list compiled
 into your version (which may differ from the list above).
 If "none" is specified for the first (or only) name, the
 --whole-file option is forced on and no checksum verification is
 performed on the transferred data. If "none" is specified for
 the second (or only) name, the --checksum option cannot be used.
 The "auto" option is the default, where rsync bases its
 algorithm choice on a negotiation between the client and the
 server as follows:
 When both sides of the transfer are at least 3.2.0, rsync
 chooses the first algorithm in the client's list of choices that
 is also in the server's list of choices. If no common checksum
 choice is found, rsync exits with an error. If the remote rsync
 is too old to support checksum negotiation, a value is chosen
 based on the protocol version (which chooses between MD5 and
 various flavors of MD4 based on protocol age).
 The default order can be customized by setting the environment
 variable RSYNC_CHECKSUM_LIST to a space-separated list of
 acceptable checksum names. If the string contains a "&"
 character, it is separated into the "client string & server
 string", otherwise the same string applies to both. If the
 string (or string portion) contains no non-whitespace
 characters, the default checksum list is used. This method does
 not allow you to specify the transfer checksum separately from
 the pre-transfer checksum, and it discards "auto" and all
 unknown checksum names. A list with only invalid names results
 in a failed negotiation.
 The use of the --checksum-choice option overrides this
 environment list.
 --one-file-system, -x
 This tells rsync to avoid crossing a filesystem boundary when
 recursing. This does not limit the user's ability to specify
 items to copy from multiple filesystems, just rsync's recursion
 through the hierarchy of each directory that the user specified,
 and also the analogous recursion on the receiving side during
 deletion. Also keep in mind that rsync treats a "bind" mount to
 the same device as being on the same filesystem.
 If this option is repeated, rsync omits all mount-point
 directories from the copy. Otherwise, it includes an empty
 directory at each mount-point it encounters (using the
 attributes of the mounted directory because those of the
 underlying mount-point directory are inaccessible).
 If rsync has been told to collapse symlinks (via --copy-links or
 --copy-unsafe-links), a symlink to a directory on another device
 is treated like a mount-point. Symlinks to non-directories are
 unaffected by this option.
 --ignore-non-existing, --existing
 This tells rsync to skip creating files (including directories)
 that do not exist yet on the destination. If this option is
 combined with the --ignore-existing option, no files will be
 updated (which can be useful if all you want to do is delete
 extraneous files).
 This option is a TRANSFER RULE, so don't expect any exclude side
 effects.
 --ignore-existing
 This tells rsync to skip updating files that already exist on
 the destination (this does not ignore existing directories, or
 nothing would get done). See also --ignore-non-existing.
 This option is a TRANSFER RULE, so don't expect any exclude side
 effects.
 This option can be useful for those doing backups using the
 --link-dest option when they need to continue a backup run that
 got interrupted. Since a --link-dest run is copied into a new
 directory hierarchy (when it is used properly), using [--ignore-
 existing will ensure that the already-handled files don't get
 tweaked (which avoids a change in permissions on the hard-linked
 files). This does mean that this option is only looking at the
 existing files in the destination hierarchy itself.
 When --info=skip2 is used rsync will output "FILENAME exists
 (INFO)" messages where the INFO indicates one of "type change",
 "sum change" (requires -c), "file change" (based on the quick
 check), "attr change", or "uptodate". Using --info=skip1 (which
 is also implied by 2 -v options) outputs the exists message
 without the INFO suffix.
 --remove-source-files
 This tells rsync to remove from the sending side the files
 (meaning non-directories) that are a part of the transfer and
 have been successfully duplicated on the receiving side.
 Note that you should only use this option on source files that
 are quiescent. If you are using this to move files that show up
 in a particular directory over to another host, make sure that
 the finished files get renamed into the source directory, not
 directly written into it, so that rsync can't possibly transfer
 a file that is not yet fully written. If you can't first write
 the files into a different directory, you should use a naming
 idiom that lets rsync avoid transferring files that are not yet
 finished (e.g. name the file "foo.new" when it is written,
 rename it to "foo" when it is done, and then use the option
 --exclude='*.new' for the rsync transfer).
 Starting with 3.1.0, rsync will skip the sender-side removal
 (and output an error) if the file's size or modify time has not
 stayed unchanged.
 Starting with 3.2.6, a local rsync copy will ensure that the
 sender does not remove a file the receiver just verified, such
 as when the user accidentally makes the source and destination
 directory the same path.
 --delete
 This tells rsync to delete extraneous files from the receiving
 side (ones that aren't on the sending side), but only for the
 directories that are being synchronized. You must have asked
 rsync to send the whole directory (e.g. "dir" or "dir/") without
 using a wildcard for the directory's contents (e.g. "dir/*")
 since the wildcard is expanded by the shell and rsync thus gets
 a request to transfer individual files, not the files' parent
 directory. Files that are excluded from the transfer are also
 excluded from being deleted unless you use the --delete-excluded
 option or mark the rules as only matching on the sending side
 (see the include/exclude modifiers in the FILTER RULES section).
 Prior to rsync 2.6.7, this option would have no effect unless
 --recursive was enabled. Beginning with 2.6.7, deletions will
 also occur when --dirs (-d) is enabled, but only for directories
 whose contents are being copied.
 This option can be dangerous if used incorrectly! It is a very
 good idea to first try a run using the --dry-run (-n) option to
 see what files are going to be deleted.
 If the sending side detects any I/O errors, then the deletion of
 any files at the destination will be automatically disabled.
 This is to prevent temporary filesystem failures (such as NFS
 errors) on the sending side from causing a massive deletion of
 files on the destination. You can override this with the
 --ignore-errors option.
 The --delete option may be combined with one of the --delete-
 WHEN options without conflict, as well as --delete-excluded.
 However, if none of the --delete-WHEN options are specified,
 rsync will choose the --delete-during algorithm when talking to
 rsync 3.0.0 or newer, or the --delete-before algorithm when
 talking to an older rsync. See also --delete-delay and
 --delete-after.
 --delete-before
 Request that the file-deletions on the receiving side be done
 before the transfer starts. See --delete (which is implied) for
 more details on file-deletion.
 Deleting before the transfer is helpful if the filesystem is
 tight for space and removing extraneous files would help to make
 the transfer possible. However, it does introduce a delay
 before the start of the transfer, and this delay might cause the
 transfer to timeout (if --timeout was specified). It also
 forces rsync to use the old, non-incremental recursion algorithm
 that requires rsync to scan all the files in the transfer into
 memory at once (see --recursive).
 --delete-during, --del
 Request that the file-deletions on the receiving side be done
 incrementally as the transfer happens. The per-directory delete
 scan is done right before each directory is checked for updates,
 so it behaves like a more efficient --delete-before, including
 doing the deletions prior to any per-directory filter files
 being updated. This option was first added in rsync version
 2.6.4. See --delete (which is implied) for more details on
 file-deletion.
 --delete-delay
 Request that the file-deletions on the receiving side be
 computed during the transfer (like --delete-during), and then
 removed after the transfer completes. This is useful when
 combined with --delay-updates and/or --fuzzy, and is more
 efficient than using --delete-after (but can behave differently,
 since --delete-after computes the deletions in a separate pass
 after all updates are done). If the number of removed files
 overflows an internal buffer, a temporary file will be created
 on the receiving side to hold the names (it is removed while
 open, so you shouldn't see it during the transfer). If the
 creation of the temporary file fails, rsync will try to fall
 back to using --delete-after (which it cannot do if --recursive
 is doing an incremental scan). See --delete (which is implied)
 for more details on file-deletion.
 --delete-after
 Request that the file-deletions on the receiving side be done
 after the transfer has completed. This is useful if you are
 sending new per-directory merge files as a part of the transfer
 and you want their exclusions to take effect for the delete
 phase of the current transfer. It also forces rsync to use the
 old, non-incremental recursion algorithm that requires rsync to
 scan all the files in the transfer into memory at once (see
 --recursive). See --delete (which is implied) for more details
 on file-deletion.
 See also the --delete-delay option that might be a faster choice
 for those that just want the deletions to occur at the end of
 the transfer.
 --delete-excluded
 This option turns any unqualified exclude/include rules into
 server-side rules that do not affect the receiver's deletions.
 By default, an exclude or include has both a server-side effect
 (to "hide" and "show" files when building the server's file
 list) and a receiver-side effect (to "protect" and "risk" files
 when deletions are occurring). Any rule that has no modifier to
 specify what sides it is executed on will be instead treated as
 if it were a server-side rule only, avoiding any "protect"
 effects of the rules.
 A rule can still apply to both sides even with this option
 specified if the rule is given both the sender & receiver
 modifier letters (e.g., -f'-sr foo'). Receiver-side
 protect/risk rules can also be explicitly specified to limit the
 deletions. This saves you from having to edit a bunch of
 -f'- foo' rules into -f'-s foo' (aka -f'H foo') rules (not to
 mention the corresponding includes).
 See the FILTER RULES section for more information. See --delete
 (which is implied) for more details on deletion.
 --ignore-missing-args
 When rsync is first processing the explicitly requested source
 files (e.g. command-line arguments or --files-from entries), it
 is normally an error if the file cannot be found. This option
 suppresses that error, and does not try to transfer the file.
 This does not affect subsequent vanished-file errors if a file
 was initially found to be present and later is no longer there.
 --delete-missing-args
 This option takes the behavior of the (implied) --ignore-
 missing-args option a step farther: each missing arg will become
 a deletion request of the corresponding destination file on the
 receiving side (should it exist). If the destination file is a
 non-empty directory, it will only be successfully deleted if
 --force-delete or --delete are in effect. Other than that, this
 option is independent of any other type of delete processing.
 The missing source files are represented by special file-list
 entries which display as a "*missing" entry in the --list-only
 output.
 --ignore-errors
 Tells --delete to go ahead and delete files even when there are
 I/O errors.
 --force-delete, --force
 This option tells rsync to delete a non-empty directory when it
 is to be replaced by a non-directory. This is only relevant if
 deletions are not active (see --delete for details).
 Note that some older rsync versions used to require --force when
 using --delete-after, and it used to be non-functional unless
 the --recursive option was also enabled.
 --max-delete=NUM
 This tells rsync not to delete more than NUM files or
 directories. If that limit is exceeded, all further deletions
 are skipped through the end of the transfer. At the end, rsync
 outputs a warning (including a count of the skipped deletions)
 and exits with an error code of 25 (unless some more important
 error condition also occurred).
 Beginning with version 3.0.0, you may specify --max-delete=0 to
 be warned about any extraneous files in the destination without
 removing any of them. Older clients interpreted this as
 "unlimited", so if you don't know what version the client is,
 you can use the less obvious --max-delete=-1 as a backward-
 compatible way to specify that no deletions be allowed (though
 really old versions didn't warn when the limit was exceeded).
 --max-size=SIZE
 This tells rsync to avoid transferring any file that is larger
 than the specified SIZE. A numeric value can be suffixed with a
 string to indicate the numeric units or left unqualified to
 specify bytes. Feel free to use a fractional value along with
 the units, such as --max-size=1.5m.
 This option is a TRANSFER RULE, so don't expect any exclude side
 effects.
 The first letter of a units string can be B (bytes), K (kilo), M
 (mega), G (giga), T (tera), or P (peta). If the string is a
 single char or has "ib" added to it (e.g. "G" or "GiB") then the
 units are multiples of 1024. If you use a two-letter suffix
 that ends with a "B" (e.g. "kb") then you get units that are
 multiples of 1000. The string's letters can be any mix of upper
 and lower-case that you want to use.
 Finally, if the string ends with either "+1" or "-1", it is
 offset by one byte in the indicated direction. The largest
 possible value is usually 8192P-1.
 Examples: --max-size=1.5mb-1 is 1499999 bytes, and --max-
 size=2g+1 is 2147483649 bytes.
 Note that rsync versions prior to 3.1.0 did not allow --max-
 size=0.
 --min-size=SIZE
 This tells rsync to avoid transferring any file that is smaller
 than the specified SIZE, which can help in not transferring
 small, junk files. See the --max-size option for a description
 of SIZE and other info.
 Note that rsync versions prior to 3.1.0 did not allow --min-
 size=0.
 --max-alloc=SIZE
 By default rsync limits an individual malloc/realloc to about
 1GB in size. For most people this limit works just fine and
 prevents a protocol error causing rsync to request massive
 amounts of memory. However, if you have many millions of files
 in a transfer, a large amount of server memory, and you don't
 want to split up your transfer into multiple parts, you can
 increase the per-allocation limit to something larger and rsync
 will consume more memory.
 Keep in mind that this is not a limit on the total size of
 allocated memory. It is a sanity-check value for each
 individual allocation.
 See the --max-size option for a description of how SIZE can be
 specified. The default suffix if none is given is bytes.
 Beginning in 3.2.7, a value of 0 is an easy way to specify
 SIZE_MAX (the largest limit possible).
 You can set a default value using the environment variable
 RSYNC_MAX_ALLOC using the same SIZE values as supported by this
 option. If the remote rsync doesn't understand the --max-alloc
 option, you can override an environmental value by specifying
 --max-alloc=1g, which will make rsync avoid sending the option
 to the remote side (because "1G" is the default).
 --block-size=SIZE, -B
 This forces the block size used in rsync's delta-transfer
 algorithm to a fixed value. It is normally selected based on
 the size of each file being updated. See the technical report
 for details.
 Beginning in 3.2.3 the SIZE can be specified with a suffix as
 detailed in the --max-size option. Older versions only accepted
 a byte count.
 --rsh=COMMAND, -e
 This option allows you to choose an alternative remote shell
 program to use for communication between the local and remote
 copies of rsync. Typically, rsync is configured to use ssh by
 default, but you may prefer to use rsh on a local network.
 If this option is used with [user@]host::module/path, then the
 remote shell COMMAND will be used to run an rsync daemon on the
 remote host, and all data will be transmitted through that
 remote shell connection, rather than through a direct socket
 connection to a running rsync daemon on the remote host. See
 the USING RSYNC-DAEMON FEATURES VIA A REMOTE-SHELL CONNECTION
 section above.
 Beginning with rsync 3.2.0, the RSYNC_PORT environment variable
 will be set when a daemon connection is being made via a remote-
 shell connection. It is set to 0 if the default daemon port is
 being assumed, or it is set to the value of the rsync port that
 was specified via either the --port option or a non-empty port
 value in an rsync:// URL. This allows the script to discern if
 a non-default port is being requested, allowing for things such
 as an SSL or stunnel helper script to connect to a default or
 alternate port.
 Command-line arguments are permitted in COMMAND provided that
 COMMAND is presented to rsync as a single argument. You must
 use spaces (not tabs or other whitespace) to separate the
 command and args from each other, and you can use single- and/or
 double-quotes to preserve spaces in an argument (but not
 backslashes). Note that doubling a single-quote inside a
 single-quoted string gives you a single-quote; likewise for
 double-quotes (though you need to pay attention to which quotes
 your shell is parsing and which quotes rsync is parsing). Some
 examples:
 -e 'ssh -p 2234'
 -e 'ssh -o "ProxyCommand nohup ssh firewall nc -w1 %h %p"'
 (Note that ssh users can alternately customize site-specific
 connect options in their .ssh/config file.)
 You can also choose the remote shell program using the RSYNC_RSH
 environment variable, which accepts the same range of values as
 -e.
 See also the --blocking-io option which is affected by this
 option.
 --rsync-path=PROGRAM
 Use this to specify what program is to be run on the remote
 machine to start-up rsync. Often used when rsync is not in the
 default remote-shell's path (e.g. --rsync-
 path=/usr/local/bin/rsync). Note that PROGRAM is run with the
 help of a shell, so it can be any program, script, or command
 sequence you'd care to run, so long as it does not corrupt the
 standard-in & standard-out that rsync is using to communicate.
 One tricky example is to set a different default directory on
 the remote machine for use with the --relative option. For
 instance:
 rsync -avR --rsync-path="cd /a/b && rsync" host:c/d /e/
 --remote-option=OPTION, -M
 This option is used for more advanced situations where you want
 certain effects to be limited to one side of the transfer only.
 For instance, if you want to pass --log-file=FILE and --fake-
 super to the remote system, specify it like this:
 rsync -av -M --log-file=foo -M--fake-super src/ dest/
 If you want to have an option affect only the local side of a
 transfer when it normally affects both sides, send its negation
 to the remote side. Like this:
 rsync -av -x -M--no-x src/ dest/
 Be cautious using this, as it is possible to toggle an option
 that will cause rsync to have a different idea about what data
 to expect next over the socket, and that will make it fail in a
 cryptic fashion.
 Note that you should use a separate -M option for each remote
 option you want to pass. On older rsync versions, the presence
 of any spaces in the remote-option arg could cause it to be
 split into separate remote args, but this requires the use of
 --old-args in a modern rsync.
 When performing a local transfer, the "local" side is the sender
 and the "remote" side is the receiver.
 Note some versions of the popt option-parsing library have a bug
 in them that prevents you from using an adjacent arg with an
 equal in it next to a short option letter (e.g. -M--log-
 file=/tmp/foo). If this bug affects your version of popt, you
 can use the version of popt that is included with rsync.
 --cvs-exclude, -C
 This is a useful shorthand for excluding a broad range of files
 that you often don't want to transfer between systems. It uses
 a similar algorithm to CVS to determine if a file should be
 ignored.
 The exclude list is initialized to exclude the following items
 (these initial items are marked as perishable -- see the FILTER
 RULES section):
 RCS SCCS CVS CVS.adm RCSLOG cvslog.* tags TAGS .make.state
 .nse_depinfo *~ #* .#* ,* _$* *$ *.old *.bak *.BAK *.orig
 *.rej .del-* *.a *.olb *.o *.obj *.so *.exe *.Z *.elc *.ln
 core .svn/ .git/ .hg/ .bzr/
 then, files listed in a $HOME/.cvsignore are added to the list
 and any files listed in the CVSIGNORE environment variable (all
 cvsignore names are delimited by whitespace).
 Finally, any file is ignored if it is in the same directory as a
 .cvsignore file and matches one of the patterns listed therein.
 Unlike rsync's filter/exclude files, these patterns are split on
 whitespace. See the cvs(1)  manual for more information.
 If you're combining -C with your own --filter rules, you should
 note that these CVS excludes are appended at the end of your own
 rules, regardless of where the -C was placed on the command-
 line. This makes them a lower priority than any rules you
 specified explicitly. If you want to control where these CVS
 excludes get inserted into your filter rules, you should omit
 the -C as a command-line option and use a combination of
 --filter=:C and --filter=-C (either on your command-line or by
 putting the ":C" and "-C" rules into a filter file with your
 other rules). The first option turns on the per-directory
 scanning for the .cvsignore file. The second option does a one-
 time import of the CVS excludes mentioned above.
 --filter=RULE, -f
 This option allows you to add rules to selectively exclude
 certain files from the list of files to be transferred. This is
 most useful in combination with a recursive transfer.
 You may use as many --filter options on the command line as you
 like to build up the list of files to exclude. If the filter
 contains whitespace, be sure to quote it so that the shell gives
 the rule to rsync as a single argument. The text below also
 mentions that you can use an underscore to replace the space
 that separates a rule from its arg.
 See the FILTER RULES section for detailed information on this
 option.
 -F The -F option is a shorthand for adding two --filter rules to
 your command. The first time it is used is a shorthand for this
 rule:
 --filter='dir-merge /.rsync-filter'
 This tells rsync to look for per-directory .rsync-filter files
 that have been sprinkled through the hierarchy and use their
 rules to filter the files in the transfer. If -F is repeated,
 it is a shorthand for this rule:
 --filter='exclude .rsync-filter'
 This filters out the .rsync-filter files themselves from the
 transfer.
 See the FILTER RULES section for detailed information on how
 these options work.
 --exclude=PATTERN
 This option is a simplified form of the --filter option that
 specifies an exclude rule and does not allow the full rule-
 parsing syntax of normal filter rules. This is equivalent to
 specifying -f'- PATTERN'.
 See the FILTER RULES section for detailed information on this
 option.
 --exclude-from=FILE
 This option is related to the --exclude option, but it specifies
 a FILE that contains exclude patterns (one per line). Blank
 lines in the file are ignored, as are whole-line comments that
 start with ';' or '#' (filename rules that contain those
 characters are unaffected).
 If a line begins with "- " (dash, space) or "+ " (plus, space),
 then the type of rule is being explicitly specified as an
 exclude or an include (respectively). Any rules without such a
 prefix are taken to be an exclude.
 If a line consists of just "!", then the current filter rules
 are cleared before adding any further rules.
 If FILE is '-', the list will be read from standard input.
 --include=PATTERN
 This option is a simplified form of the --filter option that
 specifies an include rule and does not allow the full rule-
 parsing syntax of normal filter rules. This is equivalent to
 specifying -f'+ PATTERN'.
 See the FILTER RULES section for detailed information on this
 option.
 --include-from=FILE
 This option is related to the --include option, but it specifies
 a FILE that contains include patterns (one per line). Blank
 lines in the file are ignored, as are whole-line comments that
 start with ';' or '#' (filename rules that contain those
 characters are unaffected).
 If a line begins with "- " (dash, space) or "+ " (plus, space),
 then the type of rule is being explicitly specified as an
 exclude or an include (respectively). Any rules without such a
 prefix are taken to be an include.
 If a line consists of just "!", then the current filter rules
 are cleared before adding any further rules.
 If FILE is '-', the list will be read from standard input.
 --files-from=FILE
 Using this option allows you to specify the exact list of files
 to transfer (as read from the specified FILE or '-' for standard
 input). It also tweaks the default behavior of rsync to make
 transferring just the specified files and directories easier:
 o The --relative (-R) option is implied, which preserves
 the path information that is specified for each item in
 the file (use --no-relative or --no-R if you want to turn
 that off).
 o The --dirs (-d) option is implied, which will create
 directories specified in the list on the destination
 rather than noisily skipping them (use --no-dirs or --no-
 d if you want to turn that off).
 o The --archive (-a) option's behavior does not imply
 --recursive (-r), so specify it explicitly, if you want
 it.
 o These side-effects change the default state of rsync, so
 the position of the --files-from option on the command-
 line has no bearing on how other options are parsed (e.g.
 -a works the same before or after --files-from, as does
 --no-R and all other options).
 The filenames that are read from the FILE are all relative to
 the source dir -- any leading slashes are removed and no ".."
 references are allowed to go higher than the source dir. For
 example, take this command:
 rsync -a --files-from=/tmp/foo /usr remote:/backup
 If /tmp/foo contains the string "bin" (or even "/bin"), the
 /usr/bin directory will be created as /backup/bin on the remote
 host. If it contains "bin/" (note the trailing slash), the
 immediate contents of the directory would also be sent (without
 needing to be explicitly mentioned in the file -- this began in
 version 2.6.4). In both cases, if the -r option was enabled,
 that dir's entire hierarchy would also be transferred (keep in
 mind that -r needs to be specified explicitly with --files-from,
 since it is not implied by -a. Also note that the effect of the
 (enabled by default) -r option is to duplicate only the path
 info that is read from the file -- it does not force the
 duplication of the source-spec path (/usr in this case).
 In addition, the --files-from file can be read from the remote
 host instead of the local host if you specify a "host:" in front
 of the file (the host must match one end of the transfer). As a
 short-cut, you can specify just a prefix of ":" to mean "use the
 remote end of the transfer". For example:
 rsync -a --files-from=:/path/file-list src:/ /tmp/copy
 This would copy all the files specified in the /path/file-list
 file that was located on the remote "src" host.
 If the --iconv and --secluded-args options are specified and the
 --files-from filenames are being sent from one host to another,
 the filenames will be translated from the sending host's charset
 to the receiving host's charset.
 NOTE: sorting the list of files in the --files-from input helps
 rsync to be more efficient, as it will avoid re-visiting the
 path elements that are shared between adjacent entries. If the
 input is not sorted, some path elements (implied directories)
 may end up being scanned multiple times, and rsync will
 eventually unduplicate them after they get turned into file-list
 elements.
 --from0, -0
 This tells rsync that the rules/filenames it reads from a file
 are terminated by a null ('0円') character, not a NL, CR, or
 CR+LF. This affects --exclude-from, --include-from, --files-
 from, and any merged files specified in a --filter rule. It
 does not affect --cvs-exclude (since all names read from a
 .cvsignore file are split on whitespace).
 --old-args
 This option tells rsync to stop trying to protect the arg values
 on the remote side from unintended word-splitting or other
 misinterpretation. It also allows the client to treat an empty
 arg as a "." instead of generating an error.
 The default in a modern rsync is for "shell-active" characters
 (including spaces) to be backslash-escaped in the args that are
 sent to the remote shell. The wildcard characters *, ?, [, & ]
 are not escaped in filename args (allowing them to expand into
 multiple filenames) while being protected in option args, such
 as --usermap.
 If you have a script that wants to use old-style arg splitting
 in its filenames, specify this option once. If the remote shell
 has a problem with any backslash escapes at all, specify this
 option twice.
 You may also control this setting via the RSYNC_OLD_ARGS
 environment variable. If it has the value "1", rsync will
 default to a single-option setting. If it has the value "2" (or
 more), rsync will default to a repeated-option setting. If it
 is "0", you'll get the default escaping behavior. The
 environment is always overridden by manually specified positive
 or negative options (the negative is --no-old-args).
 Note that this option also disables the extra safety check added
 in 3.2.5 that ensures that a remote sender isn't including extra
 top-level items in the file-list that you didn't request. This
 side-effect is necessary because we can't know for sure what
 names to expect when the remote shell is interpreting the args.
 This option conflicts with the --secluded-args option.
 --secluded-args, -s
 This option sends all filenames and most options to the remote
 rsync via the protocol (not the remote shell command line) which
 avoids letting the remote shell modify them. Wildcards are
 expanded on the remote host by rsync instead of a shell.
 This is similar to the default backslash-escaping of args that
 was added in 3.2.4 (see --old-args) in that it prevents things
 like space splitting and unwanted special-character side-
 effects. However, it has the drawbacks of being incompatible
 with older rsync versions (prior to 3.0.0) and of being refused
 by restricted shells that want to be able to inspect all the
 option values for safety.
 This option is useful for those times that you need the
 argument's character set to be converted for the remote host, if
 the remote shell is incompatible with the default backslash-
 escpaing method, or there is some other reason that you want the
 majority of the options and arguments to bypass the command-line
 of the remote shell.
 If you combine this option with --iconv, the args related to the
 remote side will be translated from the local to the remote
 character-set. The translation happens before wild-cards are
 expanded. See also the --files-from option.
 You may also control this setting via the RSYNC_PROTECT_ARGS
 environment variable. If it has a non-zero value, this setting
 will be enabled by default, otherwise it will be disabled by
 default. Either state is overridden by a manually specified
 positive or negative version of this option (note that --no-s
 and --no-secluded-args are the negative versions). This
 environment variable is also superseded by a non-zero
 RSYNC_OLD_ARGS export.
 This option conflicts with the --old-args option.
 This option used to be called --protect-args (before 3.2.6) and
 that older name can still be used (though specifying it as -s is
 always the easiest and most compatible choice).
 --trust-sender
 This option disables two extra validation checks that a local
 client performs on the file list generated by a remote sender.
 This option should only be used if you trust the sender to not
 put something malicious in the file list (something that could
 possibly be done via a modified rsync, a modified shell, or some
 other similar manipulation).
 Normally, the rsync client (as of version 3.2.5) runs two extra
 validation checks when pulling files from a remote rsync:
 o It verifies that additional arg items didn't get added at
 the top of the transfer.
 o It verifies that none of the items in the file list are
 names that should have been excluded (if filter rules
 were specified).
 Note that various options can turn off one or both of these
 checks if the option interferes with the validation. For
 instance:
 o Using a per-directory filter file reads filter rules that
 only the server knows about, so the filter checking is
 disabled.
 o Using the --old-args option allows the sender to
 manipulate the requested args, so the arg checking is
 disabled.
 o Reading the files-from list from the server side means
 that the client doesn't know the arg list, so the arg
 checking is disabled.
 o Using --read-batch disables both checks since the batch
 file's contents will have been verified when it was
 created.
 This option may help an under-powered client server if the extra
 pattern matching is slowing things down on a huge transfer. It
 can also be used to work around a currently-unknown bug in the
 verification logic for a transfer from a trusted sender.
 When using this option it is a good idea to specify a dedicated
 destination directory, as discussed in the MULTI-HOST SECURITY
 section.
 --copy-as=USER[:GROUP]
 This option instructs rsync to use the USER and (if specified
 after a colon) the GROUP for the copy operations. This only
 works if the user that is running rsync has the ability to
 change users. If the group is not specified then the user's
 default groups are used.
 This option can help to reduce the risk of an rsync being run as
 root into or out of a directory that might have live changes
 happening to it and you want to make sure that root-level read
 or write actions of system files are not possible. While you
 could alternatively run all of rsync as the specified user,
 sometimes you need the root-level host-access credentials to be
 used, so this allows rsync to drop root for the copying part of
 the operation after the remote-shell or daemon connection is
 established.
 The option only affects one side of the transfer unless the
 transfer is local, in which case it affects both sides. Use the
 --remote-option to affect the remote side, such as -M--copy-
 as=joe. For a local transfer, the lsh (or lsh.sh) support file
 provides a local-shell helper script that can be used to allow a
 "localhost:" or "lh:" host-spec to be specified without needing
 to setup any remote shells, allowing you to specify remote
 options that affect the side of the transfer that is using the
 host-spec (and using hostname "lh" avoids the overriding of the
 remote directory to the user's home dir).
 For example, the following rsync writes the local files as user
 "joe":
 sudo rsync -aiv --copy-as=joe host1:backups/joe/ /home/joe/
 This makes all files owned by user "joe", limits the groups to
 those that are available to that user, and makes it impossible
 for the joe user to do a timed exploit of the path to induce a
 change to a file that the joe user has no permissions to change.
 The following command does a local copy into the "dest/" dir as
 user "joe" (assuming you've installed support/lsh into a dir on
 your $PATH):
 sudo rsync -aive lsh -M--copy-as=joe src/ lh:dest/
 --temp-dir=DIR, -T
 This option instructs rsync to use DIR as a scratch directory
 when creating temporary copies of the files transferred on the
 receiving side. The default behavior is to create each
 temporary file in the same directory as the associated
 destination file. Beginning with rsync 3.1.1, the temp-file
 names inside the specified DIR will not be prefixed with an
 extra dot (though they will still have a random suffix added).
 This option is most often used when the receiving disk partition
 does not have enough free space to hold a copy of the largest
 file in the transfer. In this case (i.e. when the scratch
 directory is on a different disk partition), rsync will not be
 able to rename each received temporary file over the top of the
 associated destination file, but instead must copy it into
 place. Rsync does this by copying the file over the top of the
 destination file, which means that the destination file will
 contain truncated data during this copy. If this were not done
 this way (even if the destination file were first removed, the
 data locally copied to a temporary file in the destination
 directory, and then renamed into place) it would be possible for
 the old file to continue taking up disk space (if someone had it
 open), and thus there might not be enough room to fit the new
 version on the disk at the same time.
 If you are using this option for reasons other than a shortage
 of disk space, you may wish to combine it with the --delay-
 updates option, which will ensure that all copied files get put
 into subdirectories in the destination hierarchy, awaiting the
 end of the transfer. If you don't have enough room to duplicate
 all the arriving files on the destination partition, another way
 to tell rsync that you aren't overly concerned about disk space
 is to use the --partial-dir option with a relative path; because
 this tells rsync that it is OK to stash off a copy of a single
 file in a subdir in the destination hierarchy, rsync will use
 the partial-dir as a staging area to bring over the copied file,
 and then rename it into place from there. (Specifying a
 --partial-dir with an absolute path does not have this side-
 effect.)
 --fuzzy, -y
 This option tells rsync that it should look for a basis file for
 any destination file that is missing. The current algorithm
 looks in the same directory as the destination file for either a
 file that has an identical size and modified-time, or a
 similarly-named file. If found, rsync uses the fuzzy basis file
 to try to speed up the transfer.
 If the option is repeated, the fuzzy scan will also be done in
 any matching alternate destination directories that are
 specified via --compare-dest, --copy-dest, or --link-dest.
 Note that the use of the --delete option might get rid of any
 potential fuzzy-match files, so either use --delete-after or
 specify some filename exclusions if you need to prevent this.
 --compare-dest=DIR
 This option instructs rsync to use DIR on the destination
 machine as an additional hierarchy to compare destination files
 against doing transfers (if the files are missing in the
 destination directory). If a file is found in DIR that is
 identical to the sender's file, the file will NOT be transferred
 to the destination directory. This is useful for creating a
 sparse backup of just files that have changed from an earlier
 backup. This option is typically used to copy into an empty (or
 newly created) directory.
 Beginning in version 2.6.4, multiple --compare-dest directories
 may be provided, which will cause rsync to search the list in
 the order specified for an exact match. If a match is found
 that differs only in attributes, a local copy is made and the
 attributes updated. If a match is not found, a basis file from
 one of the DIRs will be selected to try to speed up the
 transfer.
 If DIR is a relative path, it is relative to the destination
 directory. See also --copy-dest and --link-dest.
 NOTE: beginning with version 3.1.0, rsync will remove a file
 from a non-empty destination hierarchy if an exact match is
 found in one of the compare-dest hierarchies (making the end
 result more closely match a fresh copy).
 --copy-dest=DIR
 This option behaves like --compare-dest, but rsync will also
 copy unchanged files found in DIR to the destination directory
 using a local copy. This is useful for doing transfers to a new
 destination while leaving existing files intact, and then doing
 a flash-cutover when all files have been successfully
 transferred.
 Multiple --copy-dest directories may be provided, which will
 cause rsync to search the list in the order specified for an
 unchanged file. If a match is not found, a basis file from one
 of the DIRs will be selected to try to speed up the transfer.
 If DIR is a relative path, it is relative to the destination
 directory. See also --compare-dest and --link-dest.
 --link-dest=DIR
 This option behaves like --copy-dest, but unchanged files are
 hard linked from DIR to the destination directory. The files
 must be identical in all preserved attributes (e.g. permissions,
 possibly ownership) in order for the files to be linked
 together. An example:
 rsync -av --link-dest=$PWD/prior_dir host:src_dir/ new_dir/
 If files aren't linking, double-check their attributes. Also
 check if some attributes are getting forced outside of rsync's
 control, such a mount option that squishes root to a single
 user, or mounts a removable drive with generic ownership (such
 as OS X's "Ignore ownership on this volume" option).
 Beginning in version 2.6.4, multiple --link-dest directories may
 be provided, which will cause rsync to search the list in the
 order specified for an exact match (there is a limit of 20 such
 directories). If a match is found that differs only in
 attributes, a local copy is made and the attributes updated. If
 a match is not found, a basis file from one of the DIRs will be
 selected to try to speed up the transfer.
 This option works best when copying into an empty destination
 hierarchy, as existing files may get their attributes tweaked,
 and that can affect alternate destination files via hard-links.
 Also, itemizing of changes can get a bit muddled. Note that
 prior to version 3.1.0, an alternate-directory exact match would
 never be found (nor linked into the destination) when a
 destination file already exists.
 Note that if you combine this option with --ignore-times, rsync
 will not link any files together because it only links identical
 files together as a substitute for transferring the file, never
 as an additional check after the file is updated.
 If DIR is a relative path, it is relative to the destination
 directory. See also --compare-dest and --copy-dest.
 Note that rsync versions prior to 2.6.1 had a bug that could
 prevent --link-dest from working properly for a non-super-user
 when --owner (-o) was specified (or implied). You can work-
 around this bug by avoiding the -o option (or using --no-o) when
 sending to an old rsync.
 --compress, -z
 With this option, rsync compresses the file data as it is sent
 to the destination machine, which reduces the amount of data
 being transmitted -- something that is useful over a slow
 connection.
 Rsync supports multiple compression methods and will choose one
 for you unless you force the choice using the --compress-choice
 (--zc) option.
 Run rsync --version to see the default compress list compiled
 into your version.
 When both sides of the transfer are at least 3.2.0, rsync
 chooses the first algorithm in the client's list of choices that
 is also in the server's list of choices. If no common compress
 choice is found, rsync exits with an error. If the remote rsync
 is too old to support checksum negotiation, its list is assumed
 to be "zlib".
 The default order can be customized by setting the environment
 variable RSYNC_COMPRESS_LIST to a space-separated list of
 acceptable compression names. If the string contains a "&"
 character, it is separated into the "client string & server
 string", otherwise the same string applies to both. If the
 string (or string portion) contains no non-whitespace
 characters, the default compress list is used. Any unknown
 compression names are discarded from the list, but a list with
 only invalid names results in a failed negotiation.
 There are some older rsync versions that were configured to
 reject a -z option and require the use of -zz because their
 compression library was not compatible with the default zlib
 compression method. You can usually ignore this weirdness
 unless the rsync server complains and tells you to specify -zz.
 --compress-choice=STR, --zc=STR
 This option can be used to override the automatic negotiation of
 the compression algorithm that occurs when --compress is used.
 The option implies --compress unless "none" was specified, which
 instead implies --no-compress.
 The compression options that you may be able to use are:
 o zstd
 o lz4
 o zlibx
 o zlib
 o none
 Run rsync --version to see the default compress list compiled
 into your version (which may differ from the list above).
 Note that if you see an error about an option named --old-
 compress or --new-compress, this is rsync trying to send the
 --compress-choice=zlib or --compress-choice=zlibx option in a
 backward-compatible manner that more rsync versions understand.
 This error indicates that the older rsync version on the server
 will not allow you to force the compression type.
 Note that the "zlibx" compression algorithm is just the "zlib"
 algorithm with matched data excluded from the compression stream
 (to try to make it more compatible with an external zlib
 implementation).
 --compress-level=NUM, --zl=NUM
 Explicitly set the compression level to use (see --compress, -z)
 instead of letting it default. The --compress option is implied
 as long as the level chosen is not a "don't compress" level for
 the compression algorithm that is in effect (e.g. zlib
 compression treats level 0 as "off").
 The level values vary depending on the checksum in effect.
 Because rsync will negotiate a checksum choice by default (when
 the remote rsync is new enough), it can be good to combine this
 option with a --compress-choice (--zc) option unless you're sure
 of the choice in effect. For example:
 rsync -aiv --zc=zstd --zl=22 host:src/ dest/
 For zlib & zlibx compression the valid values are from 1 to 9
 with 6 being the default. Specifying --zl=0 turns compression
 off, and specifying --zl=-1 chooses the default level of 6.
 For zstd compression the valid values are from -131072 to 22
 with 3 being the default. Specifying 0 chooses the default of 3.
 For lz4 compression there are no levels, so the value is always
 0.
 If you specify a too-large or too-small value, the number is
 silently limited to a valid value. This allows you to specify
 something like --zl=999999999 and be assured that you'll end up
 with the maximum compression level no matter what algorithm was
 chosen.
 If you want to know the compression level that is in effect,
 specify --debug=nstr to see the "negotiated string" results.
 This will report something like
 "Client compress: zstd (level 3)" (along with the checksum
 choice in effect).
 --skip-compress=LIST
 NOTE: no compression method currently supports per-file
 compression changes, so this option has no effect.
 Override the list of file suffixes that will be compressed as
 little as possible. Rsync sets the compression level on a per-
 file basis based on the file's suffix. If the compression
 algorithm has an "off" level, then no compression occurs for
 those files. Other algorithms that support changing the
 streaming level on-the-fly will have the level minimized to
 reduces the CPU usage as much as possible for a matching file.
 The LIST should be one or more file suffixes (without the dot)
 separated by slashes (/). You may specify an empty string to
 indicate that no files should be skipped.
 Simple character-class matching is supported: each must consist
 of a list of letters inside the square brackets (e.g. no special
 classes, such as "[:alpha:]", are supported, and '-' has no
 special meaning).
 The characters asterisk (*) and question-mark (?) have no
 special meaning.
 Here's an example that specifies 6 suffixes to skip (since 1 of
 the 5 rules matches 2 suffixes):
 --skip-compress=gz/jpg/mp[34]/7z/bz2
 The default file suffixes in the skip-compress list in this
 version of rsync are:
 3g2 3gp 7z aac ace apk avi bz2 deb dmg ear f4v flac flv gpg
 gz iso jar jpeg jpg lrz lz lz4 lzma lzo m1a m1v m2a m2ts m2v
 m4a m4b m4p m4r m4v mka mkv mov mp1 mp2 mp3 mp4 mpa mpeg mpg
 mpv mts odb odf odg odi odm odp ods odt oga ogg ogm ogv ogx
 opus otg oth otp ots ott oxt png qt rar rpm rz rzip spx
 squashfs sxc sxd sxg sxm sxw sz tbz tbz2 tgz tlz ts txz tzo
 vob war webm webp xz z zip zst
 This list will be replaced by your --skip-compress list in all
 but one situation: a copy from a daemon rsync will add your
 skipped suffixes to its list of non-compressing files (and its
 list may be configured to a different default).
 --numeric-ids
 With this option rsync will transfer numeric group and user IDs
 rather than using user and group names and mapping them at both
 ends.
 By default rsync will use the username and groupname to
 determine what ownership to give files. The special uid 0 and
 the special group 0 are never mapped via user/group names even
 if the --numeric-ids option is not specified.
 If a user or group has no name on the source system or it has no
 match on the destination system, then the numeric ID from the
 source system is used instead. See also the use chroot setting
 in the rsyncd.conf manpage for some comments on how the chroot
 setting affects rsync's ability to look up the names of the
 users and groups and what you can do about it.
 --usermap=STRING, --groupmap=STRING
 These options allow you to specify users and groups that should
 be mapped to other values by the receiving side. The STRING is
 one or more FROM:TO pairs of values separated by commas. Any
 matching FROM value from the sender is replaced with a TO value
 from the receiver. You may specify usernames or user IDs for
 the FROM and TO values, and the FROM value may also be a wild-
 card string, which will be matched against the sender's names
 (wild-cards do NOT match against ID numbers, though see below
 for why a '*' matches everything). You may instead specify a
 range of ID numbers via an inclusive range: LOW-HIGH. For
 example:
 --usermap=0-99:nobody,wayne:admin,*:normal --groupmap=usr:1,1:usr
 The first match in the list is the one that is used. You should
 specify all your user mappings using a single --usermap option,
 and/or all your group mappings using a single --groupmap option.
 Note that the sender's name for the 0 user and group are not
 transmitted to the receiver, so you should either match these
 values using a 0, or use the names in effect on the receiving
 side (typically "root"). All other FROM names match those in
 use on the sending side. All TO names match those in use on the
 receiving side.
 Any IDs that do not have a name on the sending side are treated
 as having an empty name for the purpose of matching. This
 allows them to be matched via a "*" or using an empty name. For
 instance:
 --usermap=:nobody --groupmap=*:nobody
 When the --numeric-ids option is used, the sender does not send
 any names, so all the IDs are treated as having an empty name.
 This means that you will need to specify numeric FROM values if
 you want to map these nameless IDs to different values.
 For the --usermap option to work, the receiver will need to be
 running as a super-user (see also the --super and --fake-super
 options). For the --groupmap option to work, the receiver will
 need to have permissions to set that group.
 Starting with rsync 3.2.4, the --usermap option implies the
 --owner (-o) option while the --groupmap option implies the
 --group (-g) option (since rsync needs to have those options
 enabled for the mapping options to work).
 An older rsync client may need to use -s to avoid a complaint
 about wildcard characters, but a modern rsync handles this
 automatically.
 --chown=USER:GROUP
 This option forces all files to be owned by USER with group
 GROUP. This is a simpler interface than using --usermap &
 --groupmap directly, but it is implemented using those options
 internally so they cannot be mixed. If either the USER or GROUP
 is empty, no mapping for the omitted user/group will occur. If
 GROUP is empty, the trailing colon may be omitted, but if USER
 is empty, a leading colon must be supplied.
 If you specify "--chown=foo:bar", this is exactly the same as
 specifying "--usermap=*:foo --groupmap=*:bar", only easier (and
 with the same implied --owner and/or --group options).
 An older rsync client may need to use -s to avoid a complaint
 about wildcard characters, but a modern rsync handles this
 automatically.
 --timeout=SECONDS
 This option allows you to set a maximum I/O timeout in seconds.
 If no data is transferred for the specified time then rsync will
 exit. The default is 0, which means no timeout.
 --contimeout=SECONDS
 This option allows you to set the amount of time that rsync will
 wait for its connection to an rsync daemon to succeed. If the
 timeout is reached, rsync exits with an error.
 --address=ADDRESS
 By default rsync will bind to the wildcard address when
 connecting to an rsync daemon. The --address option allows you
 to specify a specific IP address (or hostname) to bind to.
 See also the daemon version of the --address option.
 --port=PORT
 This specifies an alternate TCP port number to use rather than
 the default of 873. This is only needed if you are using the
 double-colon (::) syntax to connect with an rsync daemon (since
 the URL syntax has a way to specify the port as a part of the
 URL).
 See also the daemon version of the --port option.
 --sockopts=OPTIONS
 This option can provide endless fun for people who like to tune
 their systems to the utmost degree. You can set all sorts of
 socket options which may make transfers faster (or slower!).
 Read the manpage for the setsockopt() system call for details on
 some of the options you may be able to set. By default no
 special socket options are set. This only affects direct socket
 connections to a remote rsync daemon.
 See also the daemon version of the --sockopts option.
 --blocking-io
 This tells rsync to use blocking I/O when launching a remote
 shell transport. If the remote shell is either rsh or remsh,
 rsync defaults to using blocking I/O, otherwise it defaults to
 using non-blocking I/O. (Note that ssh prefers non-blocking
 I/O.)
 --outbuf=MODE
 This sets the output buffering mode. The mode can be None (aka
 Unbuffered), Line, or Block (aka Full). You may specify as
 little as a single letter for the mode, and use upper or lower
 case.
 The main use of this option is to change Full buffering to Line
 buffering when rsync's output is going to a file or pipe.
 --itemize-changes, -i
 Requests a simple itemized list of the changes that are being
 made to each file, including attribute changes. This is exactly
 the same as specifying --out-format='%i %n%L'. If you repeat
 the option, unchanged files will also be output, but only if the
 receiving rsync is at least version 2.6.7 (you can use -vv with
 older versions of rsync, but that also turns on the output of
 other verbose messages).
 The "%i" escape has a cryptic output that is 11 letters long.
 The general format is like the string YXcstpoguaxf, where Y is
 replaced by the type of update being done, X is replaced by the
 file-type, and the other letters represent attributes that may
 be output if they are being modified.
 The update types that replace the Y are as follows:
 o A < means that a file is being transferred to the remote
 host (sent).
 o A > means that a file is being transferred to the local
 host (received).
 o A c means that a local change/creation is occurring for
 the item (such as the creation of a directory or the
 changing of a symlink, etc.).
 o A h means that the item is a hard link to another item
 (requires --hard-links).
 o A . means that the item is not being updated (though it
 might have attributes that are being modified).
 o A * means that the rest of the itemized-output area
 contains a message (e.g. "deleting").
 The file-types that replace the X are: f for a file, a d for a
 directory, an L for a symlink, a D for a device, and a S for a
 special file (e.g. named sockets and fifos).
 The other letters in the string indicate if some attributes of
 the file have changed, as follows:
 o "." - the attribute is unchanged.
 o "+" - the file is newly created.
 o " " - all the attributes are unchanged (all dots turn to
 spaces).
 o "?" - the change is unknown (when the remote rsync is
 old).
 o A letter indicates an attribute is being updated.
 The attribute that is associated with each letter is as follows:
 o A c means either that a regular file has a different
 checksum (requires --checksum) or that a symlink, device,
 or special file has a changed value. Note that if you
 are sending files to an rsync prior to 3.0.1, this change
 flag will be present only for checksum-differing regular
 files.
 o A s means the size of a regular file is different and
 will be updated by the file transfer.
 o A t means the modification time is different and is being
 updated to the sender's value (requires --times). An
 alternate value of T means that the modification time
 will be set to the transfer time, which happens when a
 file/symlink/device is updated without --times and when a
 symlink is changed and the receiver can't set its time.
 (Note: when using an rsync 3.0.0 client, you might see
 the s flag combined with t instead of the proper T flag
 for this time-setting failure.)
 o A p means the permissions are different and are being
 updated to the sender's value (requires --perms).
 o An o means the owner is different and is being updated to
 the sender's value (requires --owner and super-user
 privileges).
 o A g means the group is different and is being updated to
 the sender's value (requires --group and the authority to
 set the group).
 o
 o A u|n|b indicates the following information:
 u means the access (use) time is different and is
 being updated to the sender's value (requires
 --atimes)
 o n means the create time (newness) is different and
 is being updated to the sender's value (requires
 --crtimes)
 o b means that both the access and create times are
 being updated
 o The a means that the ACL information is being changed.
 o The x means that the extended attribute information is
 being changed.
 One other output is possible: when deleting files, the "%i" will
 output the string "*deleting" for each item that is being
 removed (assuming that you are talking to a recent enough rsync
 that it logs deletions instead of outputting them as a verbose
 message).
 --out-format=FORMAT
 This allows you to specify exactly what the rsync client outputs
 to the user on a per-update basis. The format is a text string
 containing embedded single-character escape sequences prefixed
 with a percent (%) character. A default format of "%n%L" is
 assumed if either --info=name or -v is specified (this tells you
 just the name of the file and, if the item is a link, where it
 points). For a full list of the possible escape characters, see
 the log format setting in the rsyncd.conf manpage.
 Specifying the --out-format option implies the --info=name
 option, which will mention each file, dir, etc. that gets
 updated in a significant way (a transferred file, a recreated
 symlink/device, or a touched directory). In addition, if the
 itemize-changes escape (%i) is included in the string (e.g. if
 the --itemize-changes option was used), the logging of names
 increases to mention any item that is changed in any way (as
 long as the receiving side is at least 2.6.4). See the
 --itemize-changes option for a description of the output of
 "%i".
 Rsync will output the out-format string prior to a file's
 transfer unless one of the transfer-statistic escapes is
 requested, in which case the logging is done at the end of the
 file's transfer. When this late logging is in effect and
 --progress is also specified, rsync will also output the name of
 the file being transferred prior to its progress information
 (followed, of course, by the out-format output).
 --log-file=FILE
 This option causes rsync to log what it is doing to a file.
 This is similar to the logging that a daemon does, but can be
 requested for the client side and/or the server side of a non-
 daemon transfer. If specified as a client option, transfer
 logging will be enabled with a default format of "%i %n%L". See
 the --log-file-format option if you wish to override this.
 Here's an example command that requests the remote side to log
 what is happening:
 rsync -av --remote-option=--log-file=/tmp/rlog src/ dest/
 This is very useful if you need to debug why a connection is
 closing unexpectedly.
 See also the daemon version of the --log-file option.
 --log-file-format=FORMAT
 This allows you to specify exactly what per-update logging is
 put into the file specified by the --log-file option (which must
 also be specified for this option to have any effect). If you
 specify an empty string, updated files will not be mentioned in
 the log file. For a list of the possible escape characters, see
 the log format setting in the rsyncd.conf manpage.
 The default FORMAT used if --log-file is specified and this
 option is not is '%i %n%L'.
 See also the daemon version of the --log-file-format option.
 --stats
 This tells rsync to print a verbose set of statistics on the
 file transfer, allowing you to tell how effective rsync's delta-
 transfer algorithm is for your data. This option is equivalent
 to --info=stats2 if combined with 0 or 1 -v options, or
 --info=stats3 if combined with 2 or more -v options.
 The current statistics are as follows:
 o Number of files is the count of all "files" (in the
 generic sense), which includes directories, symlinks,
 etc. The total count will be followed by a list of
 counts by filetype (if the total is non-zero). For
 example: "(reg: 5, dir: 3, link: 2, dev: 1, special: 1)"
 lists the totals for regular files, directories,
 symlinks, devices, and special files. If any of value is
 0, it is completely omitted from the list.
 o Number of created files is the count of how many "files"
 (generic sense) were created (as opposed to updated).
 The total count will be followed by a list of counts by
 filetype (if the total is non-zero).
 o Number of deleted files is the count of how many "files"
 (generic sense) were deleted. The total count will be
 followed by a list of counts by filetype (if the total is
 non-zero). Note that this line is only output if
 deletions are in effect, and only if protocol 31 is being
 used (the default for rsync 3.1.x).
 o Number of regular files transferred is the count of
 normal files that were updated via rsync's delta-transfer
 algorithm, which does not include dirs, symlinks, etc.
 Note that rsync 3.1.0 added the word "regular" into this
 heading.
 o Total file size is the total sum of all file sizes in the
 transfer. This does not count any size for directories
 or special files, but does include the size of symlinks.
 o Total transferred file size is the total sum of all files
 sizes for just the transferred files.
 o Literal data is how much unmatched file-update data we
 had to send to the receiver for it to recreate the
 updated files.
 o Matched data is how much data the receiver got locally
 when recreating the updated files.
 o File list size is how big the file-list data was when the
 sender sent it to the receiver. This is smaller than the
 in-memory size for the file list due to some compressing
 of duplicated data when rsync sends the list.
 o File list generation time is the number of seconds that
 the sender spent creating the file list. This requires a
 modern rsync on the sending side for this to be present.
 o File list transfer time is the number of seconds that the
 sender spent sending the file list to the receiver.
 o Total bytes sent is the count of all the bytes that rsync
 sent from the client side to the server side.
 o Total bytes received is the count of all non-message
 bytes that rsync received by the client side from the
 server side. "Non-message" bytes means that we don't
 count the bytes for a verbose message that the server
 sent to us, which makes the stats more consistent.
 --8-bit-output, -8
 This tells rsync to leave all high-bit characters unescaped in
 the output instead of trying to test them to see if they're
 valid in the current locale and escaping the invalid ones. All
 control characters (but never tabs) are always escaped,
 regardless of this option's setting.
 The escape idiom that started in 2.6.7 is to output a literal
 backslash (\) and a hash (#), followed by exactly 3 octal
 digits. For example, a newline would output as "\#012". A
 literal backslash that is in a filename is not escaped unless it
 is followed by a hash and 3 digits (0-9).
 --human-readable, -h
 Output numbers in a more human-readable format. There are 3
 possible levels:
 1. output numbers with a separator between each set of 3
 digits (either a comma or a period, depending on if the
 decimal point is represented by a period or a comma).
 2. output numbers in units of 1000 (with a character suffix
 for larger units -- see below).
 3. output numbers in units of 1024.
 The default is human-readable level 1. Each -h option increases
 the level by one. You can take the level down to 0 (to output
 numbers as pure digits) by specifying the --no-human-readable
 (--no-h) option.
 The unit letters that are appended in levels 2 and 3 are: K
 (kilo), M (mega), G (giga), T (tera), or P (peta). For example,
 a 1234567-byte file would output as 1.23M in level-2 (assuming
 that a period is your local decimal point).
 Backward compatibility note: versions of rsync prior to 3.1.0 do
 not support human-readable level 1, and they default to level 0.
 Thus, specifying one or two -h options will behave in a
 comparable manner in old and new versions as long as you didn't
 specify a --no-h option prior to one or more -h options. See
 the --list-only option for one difference.
 --partial
 By default, rsync will delete any partially transferred file if
 the transfer is interrupted. In some circumstances it is more
 desirable to keep partially transferred files. Using the
 --partial option tells rsync to keep the partial file which
 should make a subsequent transfer of the rest of the file much
 faster.
 --partial-dir=DIR
 This option modifies the behavior of the --partial option while
 also implying that it be enabled. This enhanced partial-file
 method puts any partially transferred files into the specified
 DIR instead of writing the partial file out to the destination
 file. On the next transfer, rsync will use a file found in this
 dir as data to speed up the resumption of the transfer and then
 delete it after it has served its purpose.
 Note that if --whole-file is specified (or implied), any
 partial-dir files that are found for a file that is being
 updated will simply be removed (since rsync is sending files
 without using rsync's delta-transfer algorithm).
 Rsync will create the DIR if it is missing, but just the last
 dir -- not the whole path. This makes it easy to use a relative
 path (such as "--partial-dir=.rsync-partial") to have rsync
 create the partial-directory in the destination file's directory
 when it is needed, and then remove it again when the partial
 file is deleted. Note that this directory removal is only done
 for a relative pathname, as it is expected that an absolute path
 is to a directory that is reserved for partial-dir work.
 If the partial-dir value is not an absolute path, rsync will add
 an exclude rule at the end of all your existing excludes. This
 will prevent the sending of any partial-dir files that may exist
 on the sending side, and will also prevent the untimely deletion
 of partial-dir items on the receiving side. An example: the
 above --partial-dir option would add the equivalent of this
 "perishable" exclude at the end of any other filter rules:
 -f '-p .rsync-partial/'
 If you are supplying your own exclude rules, you may need to add
 your own exclude/hide/protect rule for the partial-dir because:
 1. the auto-added rule may be ineffective at the end of your
 other rules, or
 2. you may wish to override rsync's exclude choice.
 For instance, if you want to make rsync clean-up any left-over
 partial-dirs that may be lying around, you should specify
 --delete-after and add a "risk" filter rule, e.g. -f 'R .rsync-
 partial/'. Avoid using --delete-before or --delete-during unless
 you don't need rsync to use any of the left-over partial-dir
 data during the current run.
 IMPORTANT: the --partial-dir should not be writable by other
 users or it is a security risk! E.g. AVOID "/tmp"!
 You can also set the partial-dir value the RSYNC_PARTIAL_DIR
 environment variable. Setting this in the environment does not
 force --partial to be enabled, but rather it affects where
 partial files go when --partial is specified. For instance,
 instead of using --partial-dir=.rsync-tmp along with --progress,
 you could set RSYNC_PARTIAL_DIR=.rsync-tmp in your environment
 and then use the -P option to turn on the use of the .rsync-tmp
 dir for partial transfers. The only times that the --partial
 option does not look for this environment value are:
 1. when --inplace was specified (since --inplace conflicts
 with --partial-dir), and
 2. when --delay-updates was specified (see below).
 When a modern rsync resumes the transfer of a file in the
 partial-dir, that partial file is now updated in-place instead
 of creating yet another tmp-file copy (so it maxes out at dest +
 tmp instead of dest + partial + tmp). This requires both ends
 of the transfer to be at least version 3.2.0.
 For the purposes of the daemon-config's "refuse options"
 setting, --partial-dir does not imply --partial. This is so
 that a refusal of the --partial option can be used to disallow
 the overwriting of destination files with a partial transfer,
 while still allowing the safer idiom provided by --partial-dir.
 --delay-updates
 This option puts the temporary file from each updated file into
 a holding directory until the end of the transfer, at which time
 all the files are renamed into place in rapid succession. This
 attempts to make the updating of the files a little more atomic.
 By default the files are placed into a directory named .~tmp~ in
 each file's destination directory, but if you've specified the
 --partial-dir option, that directory will be used instead. See
 the comments in the --partial-dir section for a discussion of
 how this .~tmp~ dir will be excluded from the transfer, and what
 you can do if you want rsync to cleanup old .~tmp~ dirs that
 might be lying around. Conflicts with --inplace and --append.
 This option implies --no-inc-recursive since it needs the full
 file list in memory in order to be able to iterate over it at
 the end.
 This option uses more memory on the receiving side (one bit per
 file transferred) and also requires enough free disk space on
 the receiving side to hold an additional copy of all the updated
 files. Note also that you should not use an absolute path to
 --partial-dir unless:
 1. there is no chance of any of the files in the transfer
 having the same name (since all the updated files will be
 put into a single directory if the path is absolute), and
 2. there are no mount points in the hierarchy (since the
 delayed updates will fail if they can't be renamed into
 place).
 See also the "atomic-rsync" python script in the "support"
 subdir for an update algorithm that is even more atomic (it uses
 --link-dest and a parallel hierarchy of files).
 --prune-empty-dirs, -m
 This option tells the receiving rsync to get rid of empty
 directories from the file-list, including nested directories
 that have no non-directory children. This is useful for
 avoiding the creation of a bunch of useless directories when the
 sending rsync is recursively scanning a hierarchy of files using
 include/exclude/filter rules.
 This option can still leave empty directories on the receiving
 side if you make use of TRANSFER_RULES.
 Because the file-list is actually being pruned, this option also
 affects what directories get deleted when a delete is active.
 However, keep in mind that excluded files and directories can
 prevent existing items from being deleted due to an exclude both
 hiding source files and protecting destination files. See the
 perishable filter-rule option for how to avoid this.
 You can prevent the pruning of certain empty directories from
 the file-list by using a global "protect" filter. For instance,
 this option would ensure that the directory "emptydir" was kept
 in the file-list:
 --filter 'protect emptydir/'
 Here's an example that copies all .pdf files in a hierarchy,
 only creating the necessary destination directories to hold the
 .pdf files, and ensures that any superfluous files and
 directories in the destination are removed (note the hide filter
 of non-directories being used instead of an exclude):
 rsync -avm --del --include='*.pdf' -f 'hide,! */' src/ dest
 If you didn't want to remove superfluous destination files, the
 more time-honored options of --include='*/' --exclude='*' would
 work fine in place of the hide-filter (if that is more natural
 to you).
 --progress
 This option tells rsync to print information showing the
 progress of the transfer. This gives a bored user something to
 watch. With a modern rsync this is the same as specifying
 --info=flist2,name,progress, but any user-supplied settings for
 those info flags takes precedence (e.g.
 --info=flist0 --progress).
 While rsync is transferring a regular file, it updates a
 progress line that looks like this:
 782448 63% 110.64kB/s 0:00:04
 In this example, the receiver has reconstructed 782448 bytes or
 63% of the sender's file, which is being reconstructed at a rate
 of 110.64 kilobytes per second, and the transfer will finish in
 4 seconds if the current rate is maintained until the end.
 These statistics can be misleading if rsync's delta-transfer
 algorithm is in use. For example, if the sender's file consists
 of the basis file followed by additional data, the reported rate
 will probably drop dramatically when the receiver gets to the
 literal data, and the transfer will probably take much longer to
 finish than the receiver estimated as it was finishing the
 matched part of the file.
 When the file transfer finishes, rsync replaces the progress
 line with a summary line that looks like this:
 1,238,099 100% 146.38kB/s 0:00:08 (xfr#5, to-chk=169/396)
 In this example, the file was 1,238,099 bytes long in total, the
 average rate of transfer for the whole file was 146.38 kilobytes
 per second over the 8 seconds that it took to complete, it was
 the 5th transfer of a regular file during the current rsync
 session, and there are 169 more files for the receiver to check
 (to see if they are up-to-date or not) remaining out of the 396
 total files in the file-list.
 In an incremental recursion scan, rsync won't know the total
 number of files in the file-list until it reaches the ends of
 the scan, but since it starts to transfer files during the scan,
 it will display a line with the text "ir-chk" (for incremental
 recursion check) instead of "to-chk" until the point that it
 knows the full size of the list, at which point it will switch
 to using "to-chk". Thus, seeing "ir-chk" lets you know that the
 total count of files in the file list is still going to increase
 (and each time it does, the count of files left to check will
 increase by the number of the files added to the list).
 -P The -P option is equivalent to "--partial --progress". Its
 purpose is to make it much easier to specify these two options
 for a long transfer that may be interrupted.
 There is also a --info=progress2 option that outputs statistics
 based on the whole transfer, rather than individual files. Use
 this flag without outputting a filename (e.g. avoid -v or
 specify --info=name0) if you want to see how the transfer is
 doing without scrolling the screen with a lot of names. (You
 don't need to specify the --progress option in order to use
 --info=progress2.)
 Finally, you can get an instant progress report by sending rsync
 a signal of either SIGINFO or SIGVTALRM. On BSD systems, a
 SIGINFO is generated by typing a Ctrl+T (Linux doesn't currently
 support a SIGINFO signal). When the client-side process
 receives one of those signals, it sets a flag to output a single
 progress report which is output when the current file transfer
 finishes (so it may take a little time if a big file is being
 handled when the signal arrives). A filename is output (if
 needed) followed by the --info=progress2 format of progress
 info. If you don't know which of the 3 rsync processes is the
 client process, it's OK to signal all of them (since the non-
 client processes ignore the signal).
 CAUTION: sending SIGVTALRM to an older rsync (pre-3.2.0) will
 kill it.
 --password-file=FILE
 This option allows you to provide a password for accessing an
 rsync daemon via a file or via standard input if FILE is -. The
 file should contain just the password on the first line (all
 other lines are ignored). Rsync will exit with an error if FILE
 is world readable or if a root-run rsync command finds a non-
 root-owned file.
 This option does not supply a password to a remote shell
 transport such as ssh; to learn how to do that, consult the
 remote shell's documentation. When accessing an rsync daemon
 using a remote shell as the transport, this option only comes
 into effect after the remote shell finishes its authentication
 (i.e. if you have also specified a password in the daemon's
 config file).
 --early-input=FILE
 This option allows rsync to send up to 5K of data to the "early
 exec" script on its stdin. One possible use of this data is to
 give the script a secret that can be used to mount an encrypted
 filesystem (which you should unmount in the the "post-xfer exec"
 script).
 The daemon must be at least version 3.2.1.
 --list-only
 This option will cause the source files to be listed instead of
 transferred. This option is inferred if there is a single
 source arg and no destination specified, so its main uses are:
 1. to turn a copy command that includes a destination arg
 into a file-listing command, or
 2. to be able to specify more than one source arg. Note: be
 sure to include the destination.
 CAUTION: keep in mind that a source arg with a wild-card is
 expanded by the shell into multiple args, so it is never safe to
 try to specify a single wild-card arg to try to infer this
 option. A safe example is:
 rsync -av --list-only foo* dest/
 This option always uses an output format that looks similar to
 this:
 drwxrwxr-x 4,096 2022年09月30日 12:53:11 support
 -rw-rw-r-- 80 2005年01月11日 10:37:37 support/Makefile
 The only option that affects this output style is (as of 3.1.0)
 the --human-readable (-h) option. The default is to output
 sizes as byte counts with digit separators (in a 14-character-
 width column). Specifying at least one -h option makes the
 sizes output with unit suffixes. If you want old-style
 bytecount sizes without digit separators (and an 11-character-
 width column) use --no-h.
 Compatibility note: when requesting a remote listing of files
 from an rsync that is version 2.6.3 or older, you may encounter
 an error if you ask for a non-recursive listing. This is
 because a file listing implies the --dirs option w/o
 --recursive, and older rsyncs don't have that option. To avoid
 this problem, either specify the --no-dirs option (if you don't
 need to expand a directory's content), or turn on recursion and
 exclude the content of subdirectories: -r --exclude='/*/*'.
 --bwlimit=RATE
 This option allows you to specify the maximum transfer rate for
 the data sent over the socket, specified in units per second.
 The RATE value can be suffixed with a string to indicate a size
 multiplier, and may be a fractional value (e.g. --bwlimit=1.5m).
 If no suffix is specified, the value will be assumed to be in
 units of 1024 bytes (as if "K" or "KiB" had been appended). See
 the --max-size option for a description of all the available
 suffixes. A value of 0 specifies no limit.
 For backward-compatibility reasons, the rate limit will be
 rounded to the nearest KiB unit, so no rate smaller than 1024
 bytes per second is possible.
 Rsync writes data over the socket in blocks, and this option
 both limits the size of the blocks that rsync writes, and tries
 to keep the average transfer rate at the requested limit. Some
 burstiness may be seen where rsync writes out a block of data
 and then sleeps to bring the average rate into compliance.
 Due to the internal buffering of data, the --progress option may
 not be an accurate reflection on how fast the data is being
 sent. This is because some files can show up as being rapidly
 sent when the data is quickly buffered, while other can show up
 as very slow when the flushing of the output buffer occurs.
 This may be fixed in a future version.
 See also the daemon version of the --bwlimit option.
 --stop-after=MINS, (--time-limit=MINS)
 This option tells rsync to stop copying when the specified
 number of minutes has elapsed.
 For maximal flexibility, rsync does not communicate this option
 to the remote rsync since it is usually enough that one side of
 the connection quits as specified. This allows the option's use
 even when only one side of the connection supports it. You can
 tell the remote side about the time limit using --remote-option
 (-M), should the need arise.
 The --time-limit version of this option is deprecated.
 --stop-at=y-m-dTh:m
 This option tells rsync to stop copying when the specified point
 in time has been reached. The date & time can be fully specified
 in a numeric format of year-month-dayThour:minute (e.g.
 2000年12月31日T23:59) in the local timezone. You may choose to
 separate the date numbers using slashes instead of dashes.
 The value can also be abbreviated in a variety of ways, such as
 specifying a 2-digit year and/or leaving off various values. In
 all cases, the value will be taken to be the next possible point
 in time where the supplied information matches. If the value
 specifies the current time or a past time, rsync exits with an
 error.
 For example, "1-30" specifies the next January 30th (at midnight
 local time), "14:00" specifies the next 2 P.M., "1" specifies
 the next 1st of the month at midnight, "31" specifies the next
 month where we can stop on its 31st day, and ":59" specifies the
 next 59th minute after the hour.
 For maximal flexibility, rsync does not communicate this option
 to the remote rsync since it is usually enough that one side of
 the connection quits as specified. This allows the option's use
 even when only one side of the connection supports it. You can
 tell the remote side about the time limit using --remote-option
 (-M), should the need arise. Do keep in mind that the remote
 host may have a different default timezone than your local host.
 --fsync
 Cause the receiving side to fsync each finished file. This may
 slow down the transfer, but can help to provide peace of mind
 when updating critical files.
 --write-batch=FILE
 Record a file that can later be applied to another identical
 destination with --read-batch. See the "BATCH MODE" section for
 details, and also the --only-write-batch option.
 This option overrides the negotiated checksum & compress lists
 and always negotiates a choice based on old-school md5/md4/zlib
 choices. If you want a more modern choice, use the --checksum-
 choice (--cc) and/or --compress-choice (--zc) options.
 --only-write-batch=FILE
 Works like --write-batch, except that no updates are made on the
 destination system when creating the batch. This lets you
 transport the changes to the destination system via some other
 means and then apply the changes via --read-batch.
 Note that you can feel free to write the batch directly to some
 portable media: if this media fills to capacity before the end
 of the transfer, you can just apply that partial transfer to the
 destination and repeat the whole process to get the rest of the
 changes (as long as you don't mind a partially updated
 destination system while the multi-update cycle is happening).
 Also note that you only save bandwidth when pushing changes to a
 remote system because this allows the batched data to be
 diverted from the sender into the batch file without having to
 flow over the wire to the receiver (when pulling, the sender is
 remote, and thus can't write the batch).
 --read-batch=FILE
 Apply all of the changes stored in FILE, a file previously
 generated by --write-batch. If FILE is -, the batch data will
 be read from standard input. See the "BATCH MODE" section for
 details.
 --protocol=NUM
 Force an older protocol version to be used. This is useful for
 creating a batch file that is compatible with an older version
 of rsync. For instance, if rsync 2.6.4 is being used with the
 --write-batch option, but rsync 2.6.3 is what will be used to
 run the --read-batch option, you should use "--protocol=28" when
 creating the batch file to force the older protocol version to
 be used in the batch file (assuming you can't upgrade the rsync
 on the reading system).
 --iconv=CONVERT_SPEC
 Rsync can convert filenames between character sets using this
 option. Using a CONVERT_SPEC of "." tells rsync to look up the
 default character-set via the locale setting. Alternately, you
 can fully specify what conversion to do by giving a local and a
 remote charset separated by a comma in the order
 --iconv=LOCAL,REMOTE, e.g. --iconv=utf8,iso88591. This order
 ensures that the option will stay the same whether you're
 pushing or pulling files. Finally, you can specify either --no-
 iconv or a CONVERT_SPEC of "-" to turn off any conversion. The
 default setting of this option is site-specific, and can also be
 affected via the RSYNC_ICONV environment variable.
 For a list of what charset names your local iconv library
 supports, you can run "iconv --list".
 If you specify the --secluded-args (-s) option, rsync will
 translate the filenames you specify on the command-line that are
 being sent to the remote host. See also the --files-from
 option.
 Note that rsync does not do any conversion of names in filter
 files (including include/exclude files). It is up to you to
 ensure that you're specifying matching rules that can match on
 both sides of the transfer. For instance, you can specify extra
 include/exclude rules if there are filename differences on the
 two sides that need to be accounted for.
 When you pass an --iconv option to an rsync daemon that allows
 it, the daemon uses the charset specified in its "charset"
 configuration parameter regardless of the remote charset you
 actually pass. Thus, you may feel free to specify just the
 local charset for a daemon transfer (e.g. --iconv=utf8).
 --ipv4, -4 or --ipv6, -6
 Tells rsync to prefer IPv4/IPv6 when creating sockets or running
 ssh. This affects sockets that rsync has direct control over,
 such as the outgoing socket when directly contacting an rsync
 daemon, as well as the forwarding of the -4 or -6 option to ssh
 when rsync can deduce that ssh is being used as the remote
 shell. For other remote shells you'll need to specify the
 "--rsh SHELL -4" option directly (or whatever IPv4/IPv6 hint
 options it uses).
 See also the daemon version of these options.
 If rsync was compiled without support for IPv6, the --ipv6
 option will have no effect. The rsync --version output will
 contain "no IPv6" if is the case.
 --checksum-seed=NUM
 Set the checksum seed to the integer NUM. This 4 byte checksum
 seed is included in each block and MD4 file checksum calculation
 (the more modern MD5 file checksums don't use a seed). By
 default the checksum seed is generated by the server and
 defaults to the current time(). This option is used to set a
 specific checksum seed, which is useful for applications that
 want repeatable block checksums, or in the case where the user
 wants a more random checksum seed. Setting NUM to 0 causes
 rsync to use the default of time() for checksum seed.

DAEMON OPTIONS

 The options allowed when starting an rsync daemon are as follows:
 --daemon
 This tells rsync that it is to run as a daemon. The daemon you
 start running may be accessed using an rsync client using the
 host::module or rsync://host/module/ syntax.
 If standard input is a socket then rsync will assume that it is
 being run via inetd, otherwise it will detach from the current
 terminal and become a background daemon. The daemon will read
 the config file (rsyncd.conf) on each connect made by a client
 and respond to requests accordingly.
 See the rsyncd.conf(5)  manpage for more details.
 --address=ADDRESS
 By default rsync will bind to the wildcard address when run as a
 daemon with the --daemon option. The --address option allows
 you to specify a specific IP address (or hostname) to bind to.
 This makes virtual hosting possible in conjunction with the
 --config option.
 See also the address global option in the rsyncd.conf manpage
 and the client version of the --address option.
 --bwlimit=RATE
 This option allows you to specify the maximum transfer rate for
 the data the daemon sends over the socket. The client can still
 specify a smaller --bwlimit value, but no larger value will be
 allowed.
 See the client version of the --bwlimit option for some extra
 details.
 --config=FILE
 This specifies an alternate config file than the default. This
 is only relevant when --daemon is specified. The default is
 /etc/rsyncd.conf unless the daemon is running over a remote
 shell program and the remote user is not the super-user; in that
 case the default is rsyncd.conf in the current directory
 (typically $HOME).
 --dparam=OVERRIDE, -M
 This option can be used to set a daemon-config parameter when
 starting up rsync in daemon mode. It is equivalent to adding
 the parameter at the end of the global settings prior to the
 first module's definition. The parameter names can be specified
 without spaces, if you so desire. For instance:
 rsync --daemon -M pidfile=/path/rsync.pid
 --no-detach
 When running as a daemon, this option instructs rsync to not
 detach itself and become a background process. This option is
 required when running as a service on Cygwin, and may also be
 useful when rsync is supervised by a program such as daemontools
 or AIX's System Resource Controller. --no-detach is also
 recommended when rsync is run under a debugger. This option has
 no effect if rsync is run from inetd or sshd.
 --port=PORT
 This specifies an alternate TCP port number for the daemon to
 listen on rather than the default of 873.
 See also the client version of the --port option and the port
 global setting in the rsyncd.conf manpage.
 --log-file=FILE
 This option tells the rsync daemon to use the given log-file
 name instead of using the "log file" setting in the config file.
 See also the client version of the --log-file option.
 --log-file-format=FORMAT
 This option tells the rsync daemon to use the given FORMAT
 string instead of using the "log format" setting in the config
 file. It also enables "transfer logging" unless the string is
 empty, in which case transfer logging is turned off.
 See also the client version of the --log-file-format option.
 --sockopts
 This overrides the socket options setting in the rsyncd.conf
 file and has the same syntax.
 See also the client version of the --sockopts option.
 --verbose, -v
 This option increases the amount of information the daemon logs
 during its startup phase. After the client connects, the
 daemon's verbosity level will be controlled by the options that
 the client used and the "max verbosity" setting in the module's
 config section.
 See also the client version of the --verbose option.
 --ipv4, -4 or --ipv6, -6
 Tells rsync to prefer IPv4/IPv6 when creating the incoming
 sockets that the rsync daemon will use to listen for
 connections. One of these options may be required in older
 versions of Linux to work around an IPv6 bug in the kernel (if
 you see an "address already in use" error when nothing else is
 using the port, try specifying --ipv6 or --ipv4 when starting
 the daemon).
 See also the client version of these options.
 If rsync was compiled without support for IPv6, the --ipv6
 option will have no effect. The rsync --version output will
 contain "no IPv6" if is the case.
 --help, -h
 When specified after --daemon, print a short help page
 describing the options available for starting an rsync daemon.

FILTER RULES

 The filter rules allow for custom control of several aspects of how
 files are handled:
 o Control which files the sending side puts into the file list
 that describes the transfer hierarchy
 o Control which files the receiving side protects from deletion
 when the file is not in the sender's file list
 o Control which extended attribute names are skipped when copying
 xattrs
 The rules are either directly specified via option arguments or they
 can be read in from one or more files. The filter-rule files can even
 be a part of the hierarchy of files being copied, affecting different
 parts of the tree in different ways.
 SIMPLE INCLUDE/EXCLUDE RULES
 We will first cover the basics of how include & exclude rules affect
 what files are transferred, ignoring any deletion side-effects. Filter
 rules mainly affect the contents of directories that rsync is
 "recursing" into, but they can also affect a top-level item in the
 transfer that was specified as a argument.
 The default for any unmatched file/dir is for it to be included in the
 transfer, which puts the file/dir into the sender's file list. The use
 of an exclude rule causes one or more matching files/dirs to be left
 out of the sender's file list. An include rule can be used to limit
 the effect of an exclude rule that is matching too many files.
 The order of the rules is important because the first rule that matches
 is the one that takes effect. Thus, if an early rule excludes a file,
 no include rule that comes after it can have any effect. This means
 that you must place any include overrides somewhere prior to the
 exclude that it is intended to limit.
 When a directory is excluded, all its contents and sub-contents are
 also excluded. The sender doesn't scan through any of it at all, which
 can save a lot of time when skipping large unneeded sub-trees.
 It is also important to understand that the include/exclude rules are
 applied to every file and directory that the sender is recursing into.
 Thus, if you want a particular deep file to be included, you have to
 make sure that none of the directories that must be traversed on the
 way down to that file are excluded or else the file will never be
 discovered to be included. As an example, if the directory "a/path" was
 given as a transfer argument and you want to ensure that the file
 "a/path/down/deep/wanted.txt" is a part of the transfer, then the
 sender must not exclude the directories "a/path", "a/path/down", or
 "a/path/down/deep" as it makes it way scanning through the file tree.
 When you are working on the rules, it can be helpful to ask rsync to
 tell you what is being excluded/included and why. Specifying
 --debug=FILTER or (when pulling files) -M--debug=FILTER turns on level
 1 of the FILTER debug information that will output a message any time
 that a file or directory is included or excluded and which rule it
 matched. Beginning in 3.2.4 it will also warn if a filter rule has
 trailing whitespace, since an exclude of "foo " (with a trailing space)
 will not exclude a file named "foo".
 Exclude and include rules can specify wildcard PATTERN MATCHING RULES
 (similar to shell wildcards) that allow you to match things like a file
 suffix or a portion of a filename.
 A rule can be limited to only affecting a directory by putting a
 trailing slash onto the filename.
 SIMPLE INCLUDE/EXCLUDE EXAMPLE
 With the following file tree created on the sending side:
 mkdir x/
 touch x/file.txt
 mkdir x/y/
 touch x/y/file.txt
 touch x/y/zzz.txt
 mkdir x/z/
 touch x/z/file.txt
 Then the following rsync command will transfer the file "x/y/file.txt"
 and the directories needed to hold it, resulting in the path
 "/tmp/x/y/file.txt" existing on the remote host:
 rsync -ai -f'+ x/' -f'+ x/y/' -f'+ x/y/file.txt' -f'- *' x host:/tmp/
 Aside: this copy could also have been accomplished using the -R option
 (though the 2 commands behave differently if deletions are enabled):
 rsync -aiR x/y/file.txt host:/tmp/
 The following command does not need an include of the "x" directory
 because it is not a part of the transfer (note the traililng slash).
 Running this command would copy just "/tmp/x/file.txt" because the "y"
 and "z" dirs get excluded:
 rsync -ai -f'+ file.txt' -f'- *' x/ host:/tmp/x/
 This command would omit the zzz.txt file while copying "x" and
 everything else it contains:
 rsync -ai -f'- zzz.txt' x host:/tmp/
 FILTER RULES WHEN DELETING
 By default the include & exclude filter rules affect both the sender
 (as it creates its file list) and the receiver (as it creates its file
 lists for calculating deletions). If no delete option is in effect,
 the receiver skips creating the delete-related file lists. This two-
 sided default can be manually overridden so that you are only
 specifying sender rules or receiver rules, as described in the FILTER
 RULES IN DEPTH section.
 When deleting, an exclude protects a file from being removed on the
 receiving side while an include overrides that protection (putting the
 file at risk of deletion). The default is for a file to be at risk --
 its safety depends on it matching a corresponding file from the sender.
 An example of the two-sided exclude effect can be illustrated by the
 copying of a C development directory between 2 systems. When doing a
 touch-up copy, you might want to skip copying the built executable and
 the .o files (sender hide) so that the receiving side can build their
 own and not lose any object files that are already correct (receiver
 protect). For instance:
 rsync -ai --del -f'- *.o' -f'- cmd' src host:/dest/
 Note that using -f'-p *.o' is even better than -f'- *.o' if there is a
 chance that the directory structure may have changed. The "p" modifier
 is discussed in FILTER RULE MODIFIERS.
 One final note, if your shell doesn't mind unexpanded wildcards, you
 could simplify the typing of the filter options by using an underscore
 in place of the space and leaving off the quotes. For instance,
 -f -_*.o -f -_cmd (and similar) could be used instead of the filter
 options above.
 FILTER RULES IN DEPTH
 Rsync supports old-style include/exclude rules and new-style filter
 rules. The older rules are specified using --include and --exclude as
 well as the --include-from and --exclude-from. These are limited in
 behavior but they don't require a "-" or "+" prefix. An old-style
 exclude rule is turned into a "- name" filter rule (with no modifiers)
 and an old-style include rule is turned into a "+ name" filter rule
 (with no modifiers).
 Rsync builds an ordered list of filter rules as specified on the
 command-line and/or read-in from files. New style filter rules have
 the following syntax:
 RULE [PATTERN_OR_FILENAME]
 RULE,MODIFIERS [PATTERN_OR_FILENAME]
 You have your choice of using either short or long RULE names, as
 described below. If you use a short-named rule, the ',' separating the
 RULE from the MODIFIERS is optional. The PATTERN or FILENAME that
 follows (when present) must come after either a single space or an
 underscore (_). Any additional spaces and/or underscores are considered
 to be a part of the pattern name. Here are the available rule
 prefixes:
 exclude, '-'
 specifies an exclude pattern that (by default) is both a hide
 and a protect.
 include, '+'
 specifies an include pattern that (by default) is both a show
 and a risk.
 merge, '.'
 specifies a merge-file on the client side to read for more
 rules.
 dir-merge, ':'
 specifies a per-directory merge-file. Using this kind of filter
 rule requires that you trust the sending side's filter checking,
 so it has the side-effect mentioned under the --trust-sender
 option.
 hide, 'H'
 specifies a pattern for hiding files from the transfer.
 Equivalent to a sender-only exclude, so -f'H foo' could also be
 specified as -f'-s foo'.
 show, 'S'
 files that match the pattern are not hidden. Equivalent to a
 sender-only include, so -f'S foo' could also be specified as
 -f'+s foo'.
 protect, 'P'
 specifies a pattern for protecting files from deletion.
 Equivalent to a receiver-only exclude, so -f'P foo' could also
 be specified as -f'-r foo'.
 risk, 'R'
 files that match the pattern are not protected. Equivalent to a
 receiver-only include, so -f'R foo' could also be specified as
 -f'+r foo'.
 clear, '!'
 clears the current include/exclude list (takes no arg)
 When rules are being read from a file (using merge or dir-merge), empty
 lines are ignored, as are whole-line comments that start with a '#'
 (filename rules that contain a hash character are unaffected).
 Note also that the --filter, --include, and --exclude options take one
 rule/pattern each. To add multiple ones, you can repeat the options on
 the command-line, use the merge-file syntax of the --filter option, or
 the --include-from / --exclude-from options.
 PATTERN MATCHING RULES
 Most of the rules mentioned above take an argument that specifies what
 the rule should match. If rsync is recursing through a directory
 hierarchy, keep in mind that each pattern is matched against the name
 of every directory in the descent path as rsync finds the filenames to
 send.
 The matching rules for the pattern argument take several forms:
 o If a pattern contains a / (not counting a trailing slash) or a
 "**" (which can match a slash), then the pattern is matched
 against the full pathname, including any leading directories
 within the transfer. If the pattern doesn't contain a (non-
 trailing) / or a "**", then it is matched only against the final
 component of the filename or pathname. For example, foo means
 that the final path component must be "foo" while foo/bar would
 match the last 2 elements of the path (as long as both elements
 are within the transfer).
 o A pattern that ends with a / only matches a directory, not a
 regular file, symlink, or device.
 o A pattern that starts with a / is anchored to the start of the
 transfer path instead of the end. For example, /foo/** or
 /foo/bar/** match only leading elements in the path. If the
 rule is read from a per-directory filter file, the transfer path
 being matched will begin at the level of the filter file instead
 of the top of the transfer. See the section on ANCHORING
 INCLUDE/EXCLUDE PATTERNS for a full discussion of how to specify
 a pattern that matches at the root of the transfer.
 Rsync chooses between doing a simple string match and wildcard matching
 by checking if the pattern contains one of these three wildcard
 characters: '*', '?', and '[' :
 o a '?' matches any single character except a slash (/).
 o a '*' matches zero or more non-slash characters.
 o a '**' matches zero or more characters, including slashes.
 o a '[' introduces a character class, such as [a-z] or
 [[:alpha:]], that must match one character.
 o a trailing *** in the pattern is a shorthand that allows you to
 match a directory and all its contents using a single rule. For
 example, specifying "dir_name/***" will match both the
 "dir_name" directory (as if "dir_name/" had been specified) and
 everything in the directory (as if "dir_name/**" had been
 specified).
 o a backslash can be used to escape a wildcard character, but it
 is only interpreted as an escape character if at least one
 wildcard character is present in the match pattern. For
 instance, the pattern "foo\bar" matches that single backslash
 literally, while the pattern "foo\bar*" would need to be changed
 to "foo\\bar*" to avoid the "\b" becoming just "b".
 Here are some examples of exclude/include matching:
 o Option -f'- *.o' would exclude all filenames ending with .o
 o Option -f'- /foo' would exclude a file (or directory) named foo
 in the transfer-root directory
 o Option -f'- foo/' would exclude any directory named foo
 o Option -f'- foo/*/bar' would exclude any file/dir named bar
 which is at two levels below a directory named foo (if foo is in
 the transfer)
 o Option -f'- /foo/**/bar' would exclude any file/dir named bar
 that was two or more levels below a top-level directory named
 foo (note that /foo/bar is not excluded by this)
 o Options -f'+ */' -f'+ *.c' -f'- *' would include all directories
 and .c source files but nothing else
 o Options -f'+ foo/' -f'+ foo/bar.c' -f'- *' would include only
 the foo directory and foo/bar.c (the foo directory must be
 explicitly included or it would be excluded by the "- *")
 FILTER RULE MODIFIERS
 The following modifiers are accepted after an include (+) or exclude
 (-) rule:
 o A / specifies that the include/exclude rule should be matched
 against the absolute pathname of the current item. For example,
 -f'-/ /etc/passwd' would exclude the passwd file any time the
 transfer was sending files from the "/etc" directory, and "-/
 subdir/foo" would always exclude "foo" when it is in a dir named
 "subdir", even if "foo" is at the root of the current transfer.
 o A ! specifies that the include/exclude should take effect if the
 pattern fails to match. For instance, -f'-! */' would exclude
 all non-directories.
 o A C is used to indicate that all the global CVS-exclude rules
 should be inserted as excludes in place of the "-C". No arg
 should follow.
 o An s is used to indicate that the rule applies to the sending
 side. When a rule affects the sending side, it affects what
 files are put into the sender's file list. The default is for a
 rule to affect both sides unless --delete-excluded was
 specified, in which case default rules become sender-side only.
 See also the hide (H) and show (S) rules, which are an alternate
 way to specify sending-side includes/excludes.
 o An r is used to indicate that the rule applies to the receiving
 side. When a rule affects the receiving side, it prevents files
 from being deleted. See the s modifier for more info. See also
 the protect (P) and risk (R) rules, which are an alternate way
 to specify receiver-side includes/excludes.
 o A p indicates that a rule is perishable, meaning that it is
 ignored in directories that are being deleted. For instance,
 the --cvs-exclude (-C) option's default rules that exclude
 things like "CVS" and "*.o" are marked as perishable, and will
 not prevent a directory that was removed on the source from
 being deleted on the destination.
 o An x indicates that a rule affects xattr names in xattr
 copy/delete operations (and is thus ignored when matching
 file/dir names). If no xattr-matching rules are specified, a
 default xattr filtering rule is used (see the --xattrs option).
 MERGE-FILE FILTER RULES
 You can merge whole files into your filter rules by specifying either a
 merge (.) or a dir-merge (:) filter rule (as introduced in the FILTER
 RULES section above).
 There are two kinds of merged files -- single-instance ('.') and per-
 directory (':'). A single-instance merge file is read one time, and
 its rules are incorporated into the filter list in the place of the "."
 rule. For per-directory merge files, rsync will scan every directory
 that it traverses for the named file, merging its contents when the
 file exists into the current list of inherited rules. These per-
 directory rule files must be created on the sending side because it is
 the sending side that is being scanned for the available files to
 transfer. These rule files may also need to be transferred to the
 receiving side if you want them to affect what files don't get deleted
 (see PER-DIRECTORY RULES AND DELETE below).
 Some examples:
 merge /etc/rsync/default.rules
 . /etc/rsync/default.rules
 dir-merge .per-dir-filter
 dir-merge,n- .non-inherited-per-dir-excludes
 :n- .non-inherited-per-dir-excludes
 The following modifiers are accepted after a merge or dir-merge rule:
 o A - specifies that the file should consist of only exclude
 patterns, with no other rule-parsing except for in-file
 comments.
 o A + specifies that the file should consist of only include
 patterns, with no other rule-parsing except for in-file
 comments.
 o A C is a way to specify that the file should be read in a CVS-
 compatible manner. This turns on 'n', 'w', and '-', but also
 allows the list-clearing token (!) to be specified. If no
 filename is provided, ".cvsignore" is assumed.
 o A e will exclude the merge-file name from the transfer; e.g.
 "dir-merge,e .rules" is like "dir-merge .rules" and "- .rules".
 o An n specifies that the rules are not inherited by
 subdirectories.
 o A w specifies that the rules are word-split on whitespace
 instead of the normal line-splitting. This also turns off
 comments. Note: the space that separates the prefix from the
 rule is treated specially, so "- foo + bar" is parsed as two
 rules (assuming that prefix-parsing wasn't also disabled).
 o You may also specify any of the modifiers for the "+" or "-"
 rules (above) in order to have the rules that are read in from
 the file default to having that modifier set (except for the !
 modifier, which would not be useful). For instance, "merge,-/
 .excl" would treat the contents of .excl as absolute-path
 excludes, while "dir-merge,s .filt" and ":sC" would each make
 all their per-directory rules apply only on the sending side.
 If the merge rule specifies sides to affect (via the s or r
 modifier or both), then the rules in the file must not specify
 sides (via a modifier or a rule prefix such as hide).
 Per-directory rules are inherited in all subdirectories of the
 directory where the merge-file was found unless the 'n' modifier was
 used. Each subdirectory's rules are prefixed to the inherited per-
 directory rules from its parents, which gives the newest rules a higher
 priority than the inherited rules. The entire set of dir-merge rules
 are grouped together in the spot where the merge-file was specified, so
 it is possible to override dir-merge rules via a rule that got
 specified earlier in the list of global rules. When the list-clearing
 rule ("!") is read from a per-directory file, it only clears the
 inherited rules for the current merge file.
 Another way to prevent a single rule from a dir-merge file from being
 inherited is to anchor it with a leading slash. Anchored rules in a
 per-directory merge-file are relative to the merge-file's directory, so
 a pattern "/foo" would only match the file "foo" in the directory where
 the dir-merge filter file was found.
 Here's an example filter file which you'd specify via
 --filter=". file":
 merge /home/user/.global-filter
 - *.gz
 dir-merge .rules
 + *.[ch]
 - *.o
 - foo*
 This will merge the contents of the /home/user/.global-filter file at
 the start of the list and also turns the ".rules" filename into a per-
 directory filter file. All rules read in prior to the start of the
 directory scan follow the global anchoring rules (i.e. a leading slash
 matches at the root of the transfer).
 If a per-directory merge-file is specified with a path that is a parent
 directory of the first transfer directory, rsync will scan all the
 parent dirs from that starting point to the transfer directory for the
 indicated per-directory file. For instance, here is a common filter
 (see -F):
 --filter=': /.rsync-filter'
 That rule tells rsync to scan for the file .rsync-filter in all
 directories from the root down through the parent directory of the
 transfer prior to the start of the normal directory scan of the file in
 the directories that are sent as a part of the transfer. (Note: for an
 rsync daemon, the root is always the same as the module's "path".)
 Some examples of this pre-scanning for per-directory files:
 rsync -avF /src/path/ /dest/dir
 rsync -av --filter=': ../../.rsync-filter' /src/path/ /dest/dir
 rsync -av --filter=': .rsync-filter' /src/path/ /dest/dir
 The first two commands above will look for ".rsync-filter" in "/" and
 "/src" before the normal scan begins looking for the file in
 "/src/path" and its subdirectories. The last command avoids the
 parent-dir scan and only looks for the ".rsync-filter" files in each
 directory that is a part of the transfer.
 If you want to include the contents of a ".cvsignore" in your patterns,
 you should use the rule ":C", which creates a dir-merge of the
 .cvsignore file, but parsed in a CVS-compatible manner. You can use
 this to affect where the --cvs-exclude (-C) option's inclusion of the
 per-directory .cvsignore file gets placed into your rules by putting
 the ":C" wherever you like in your filter rules. Without this, rsync
 would add the dir-merge rule for the .cvsignore file at the end of all
 your other rules (giving it a lower priority than your command-line
 rules). For example:
 cat <<EOT | rsync -avC --filter='. -' a/ b
 + foo.o
 :C
 - *.old
 EOT
 rsync -avC --include=foo.o -f :C --exclude='*.old' a/ b
 Both of the above rsync commands are identical. Each one will merge
 all the per-directory .cvsignore rules in the middle of the list rather
 than at the end. This allows their dir-specific rules to supersede the
 rules that follow the :C instead of being subservient to all your
 rules. To affect the other CVS exclude rules (i.e. the default list of
 exclusions, the contents of $HOME/.cvsignore, and the value of
 $CVSIGNORE) you should omit the -C command-line option and instead
 insert a "-C" rule into your filter rules; e.g. "--filter=-C".
 LIST-CLEARING FILTER RULE
 You can clear the current include/exclude list by using the "!" filter
 rule (as introduced in the FILTER RULES section above). The "current"
 list is either the global list of rules (if the rule is encountered
 while parsing the filter options) or a set of per-directory rules
 (which are inherited in their own sub-list, so a subdirectory can use
 this to clear out the parent's rules).
 ANCHORING INCLUDE/EXCLUDE PATTERNS
 As mentioned earlier, global include/exclude patterns are anchored at
 the "root of the transfer" (as opposed to per-directory patterns, which
 are anchored at the merge-file's directory). If you think of the
 transfer as a subtree of names that are being sent from sender to
 receiver, the transfer-root is where the tree starts to be duplicated
 in the destination directory. This root governs where patterns that
 start with a / match.
 Because the matching is relative to the transfer-root, changing the
 trailing slash on a source path or changing your use of the --relative
 option affects the path you need to use in your matching (in addition
 to changing how much of the file tree is duplicated on the destination
 host). The following examples demonstrate this.
 Let's say that we want to match two source files, one with an absolute
 path of "/home/me/foo/bar", and one with a path of "/home/you/bar/baz".
 Here is how the various command choices differ for a 2-source transfer:
 Example cmd: rsync -a /home/me /home/you /dest
 +/- pattern: /me/foo/bar
 +/- pattern: /you/bar/baz
 Target file: /dest/me/foo/bar
 Target file: /dest/you/bar/baz
 Example cmd: rsync -a /home/me/ /home/you/ /dest
 +/- pattern: /foo/bar (note missing "me")
 +/- pattern: /bar/baz (note missing "you")
 Target file: /dest/foo/bar
 Target file: /dest/bar/baz
 Example cmd: rsync -a --relative /home/me/ /home/you /dest
 +/- pattern: /home/me/foo/bar (note full path)
 +/- pattern: /home/you/bar/baz (ditto)
 Target file: /dest/home/me/foo/bar
 Target file: /dest/home/you/bar/baz
 Example cmd: cd /home; rsync -a --relative me/foo you/ /dest
 +/- pattern: /me/foo/bar (starts at specified path)
 +/- pattern: /you/bar/baz (ditto)
 Target file: /dest/me/foo/bar
 Target file: /dest/you/bar/baz
 The easiest way to see what name you should filter is to just look at
 the output when using --verbose and put a / in front of the name (use
 the --dry-run option if you're not yet ready to copy any files).
 PER-DIRECTORY RULES AND DELETE
 Without a delete option, per-directory rules are only relevant on the
 sending side, so you can feel free to exclude the merge files
 themselves without affecting the transfer. To make this easy, the 'e'
 modifier adds this exclude for you, as seen in these two equivalent
 commands:
 rsync -av --filter=': .excl' --exclude=.excl host:src/dir /dest
 rsync -av --filter=':e .excl' host:src/dir /dest
 However, if you want to do a delete on the receiving side AND you want
 some files to be excluded from being deleted, you'll need to be sure
 that the receiving side knows what files to exclude. The easiest way
 is to include the per-directory merge files in the transfer and use
 --delete-after, because this ensures that the receiving side gets all
 the same exclude rules as the sending side before it tries to delete
 anything:
 rsync -avF --delete-after host:src/dir /dest
 However, if the merge files are not a part of the transfer, you'll need
 to either specify some global exclude rules (i.e. specified on the
 command line), or you'll need to maintain your own per-directory merge
 files on the receiving side. An example of the first is this (assume
 that the remote .rules files exclude themselves):
 rsync -av --filter=': .rules' --filter='. /my/extra.rules'
 --delete host:src/dir /dest
 In the above example the extra.rules file can affect both sides of the
 transfer, but (on the sending side) the rules are subservient to the
 rules merged from the .rules files because they were specified after
 the per-directory merge rule.
 In one final example, the remote side is excluding the .rsync-filter
 files from the transfer, but we want to use our own .rsync-filter files
 to control what gets deleted on the receiving side. To do this we must
 specifically exclude the per-directory merge files (so that they don't
 get deleted) and then put rules into the local files to control what
 else should not get deleted. Like one of these commands:
 rsync -av --filter=':e /.rsync-filter' --delete \
 host:src/dir /dest
 rsync -avFF --delete host:src/dir /dest

TRANSFER RULES

 In addition to the FILTER RULES that affect the recursive file scans
 that generate the file list on the sending and (when deleting)
 receiving sides, there are transfer rules. These rules affect which
 files the generator decides need to be transferred without the side
 effects of an exclude filter rule. Transfer rules affect only files
 and never directories.
 Because a transfer rule does not affect what goes into the sender's
 (and receiver's) file list, it cannot have any effect on which files
 get deleted on the receiving side. For example, if the file "foo" is
 present in the sender's list but its size is such that it is omitted
 due to a transfer rule, the receiving side does not request the file.
 However, its presence in the file list means that a delete pass will
 not remove a matching file named "foo" on the receiving side. On the
 other hand, a server-side exclude (hide) of the file "foo" leaves the
 file out of the server's file list, and absent a receiver-side exclude
 (protect) the receiver will remove a matching file named "foo" if
 deletions are requested.
 Given that the files are still in the sender's file list, the --prune-
 empty-dirs option will not judge a directory as being empty even if it
 contains only files that the transfer rules omitted.
 Similarly, a transfer rule does not have any extra effect on which
 files are deleted on the receiving side, so setting a maximum file size
 for the transfer does not prevent big files from being deleted.
 Examples of transfer rules include the default "quick check" algorithm
 (which compares size & modify time), the --update option, the --max-
 size option, the --ignore-non-existing option, and a few others.

BATCH MODE

 Batch mode can be used to apply the same set of updates to many
 identical systems. Suppose one has a tree which is replicated on a
 number of hosts. Now suppose some changes have been made to this
 source tree and those changes need to be propagated to the other hosts.
 In order to do this using batch mode, rsync is run with the write-batch
 option to apply the changes made to the source tree to one of the
 destination trees. The write-batch option causes the rsync client to
 store in a "batch file" all the information needed to repeat this
 operation against other, identical destination trees.
 Generating the batch file once saves having to perform the file status,
 checksum, and data block generation more than once when updating
 multiple destination trees. Multicast transport protocols can be used
 to transfer the batch update files in parallel to many hosts at once,
 instead of sending the same data to every host individually.
 To apply the recorded changes to another destination tree, run rsync
 with the read-batch option, specifying the name of the same batch file,
 and the destination tree. Rsync updates the destination tree using the
 information stored in the batch file.
 For your convenience, a script file is also created when the write-
 batch option is used: it will be named the same as the batch file with
 ".sh" appended. This script file contains a command-line suitable for
 updating a destination tree using the associated batch file. It can be
 executed using a Bourne (or Bourne-like) shell, optionally passing in
 an alternate destination tree pathname which is then used instead of
 the original destination path. This is useful when the destination
 tree path on the current host differs from the one used to create the
 batch file.
 Examples:
 $ rsync --write-batch=foo -a host:/source/dir/ /adest/dir/
 $ scp foo* remote:
 $ ssh remote ./foo.sh /bdest/dir/
 $ rsync --write-batch=foo -a /source/dir/ /adest/dir/
 $ ssh remote rsync --read-batch=- -a /bdest/dir/ <foo
 In these examples, rsync is used to update /adest/dir/ from
 /source/dir/ and the information to repeat this operation is stored in
 "foo" and "foo.sh". The host "remote" is then updated with the batched
 data going into the directory /bdest/dir. The differences between the
 two examples reveals some of the flexibility you have in how you deal
 with batches:
 o The first example shows that the initial copy doesn't have to be
 local -- you can push or pull data to/from a remote host using
 either the remote-shell syntax or rsync daemon syntax, as
 desired.
 o The first example uses the created "foo.sh" file to get the
 right rsync options when running the read-batch command on the
 remote host.
 o The second example reads the batch data via standard input so
 that the batch file doesn't need to be copied to the remote
 machine first. This example avoids the foo.sh script because it
 needed to use a modified --read-batch option, but you could edit
 the script file if you wished to make use of it (just be sure
 that no other option is trying to use standard input, such as
 the --exclude-from=- option).
 Caveats:
 The read-batch option expects the destination tree that it is updating
 to be identical to the destination tree that was used to create the
 batch update fileset. When a difference between the destination trees
 is encountered the update might be discarded with a warning (if the
 file appears to be up-to-date already) or the file-update may be
 attempted and then, if the file fails to verify, the update discarded
 with an error. This means that it should be safe to re-run a read-
 batch operation if the command got interrupted. If you wish to force
 the batched-update to always be attempted regardless of the file's size
 and date, use the -I option (when reading the batch). If an error
 occurs, the destination tree will probably be in a partially updated
 state. In that case, rsync can be used in its regular (non-batch) mode
 of operation to fix up the destination tree.
 The rsync version used on all destinations must be at least as new as
 the one used to generate the batch file. Rsync will die with an error
 if the protocol version in the batch file is too new for the batch-
 reading rsync to handle. See also the --protocol option for a way to
 have the creating rsync generate a batch file that an older rsync can
 understand. (Note that batch files changed format in version 2.6.3, so
 mixing versions older than that with newer versions will not work.)
 When reading a batch file, rsync will force the value of certain
 options to match the data in the batch file if you didn't set them to
 the same as the batch-writing command. Other options can (and should)
 be changed. For instance --write-batch changes to --read-batch,
 --files-from is dropped, and the --filter / --include / --exclude
 options are not needed unless one of the --delete options is specified.
 The code that creates the BATCH.sh file transforms any
 filter/include/exclude options into a single list that is appended as a
 "here" document to the shell script file. An advanced user can use
 this to modify the exclude list if a change in what gets deleted by
 --delete is desired. A normal user can ignore this detail and just use
 the shell script as an easy way to run the appropriate --read-batch
 command for the batched data.
 The original batch mode in rsync was based on "rsync+", but the latest
 version uses a new implementation.

SYMBOLIC LINKS

 Three basic behaviors are possible when rsync encounters a symbolic
 link in the source directory.
 By default, symbolic links are not transferred at all. A message
 "skipping non-regular" file is emitted for any symlinks that exist.
 If --links is specified, then symlinks are added to the transfer
 (instead of being noisily ignored), and the default handling is to
 recreate them with the same target on the destination. Note that
 --archive implies --links.
 If --copy-links is specified, then symlinks are "collapsed" by copying
 their referent, rather than the symlink.
 Rsync can also distinguish "safe" and "unsafe" symbolic links. An
 example where this might be used is a web site mirror that wishes to
 ensure that the rsync module that is copied does not include symbolic
 links to /etc/passwd in the public section of the site. Using --copy-
 unsafe-links will cause any links to be copied as the file they point
 to on the destination. Using --safe-links will cause unsafe links to
 be omitted by the receiver. (Note that you must specify or imply
 --links for --safe-links to have any effect.)
 Symbolic links are considered unsafe if they are absolute symlinks
 (start with /), empty, or if they contain enough ".." components to
 ascend from the top of the transfer.
 Here's a summary of how the symlink options are interpreted. The list
 is in order of precedence, so if your combination of options isn't
 mentioned, use the first line that is a complete subset of your
 options:
 --copy-links
 Turn all symlinks into normal files and directories (leaving no
 symlinks in the transfer for any other options to affect).
 --copy-dirlinks
 Turn just symlinks to directories into real directories, leaving
 all other symlinks to be handled as described below.
 --links --copy-unsafe-links
 Turn all unsafe symlinks into files and create all safe
 symlinks.
 --copy-unsafe-links
 Turn all unsafe symlinks into files, noisily skip all safe
 symlinks.
 --links --safe-links
 The receiver skips creating unsafe symlinks found in the
 transfer and creates the safe ones.
 --links
 Create all symlinks.
 For the effect of --munge-links, see the discussion in that option's
 section.
 Note that the --keep-dirlinks option does not effect symlinks in the
 transfer but instead affects how rsync treats a symlink to a directory
 that already exists on the receiving side. See that option's section
 for a warning.

DIAGNOSTICS

 Rsync occasionally produces error messages that may seem a little
 cryptic. The one that seems to cause the most confusion is "protocol
 version mismatch -- is your shell clean?".
 This message is usually caused by your startup scripts or remote shell
 facility producing unwanted garbage on the stream that rsync is using
 for its transport. The way to diagnose this problem is to run your
 remote shell like this:
 ssh remotehost /bin/true > out.dat
 then look at out.dat. If everything is working correctly then out.dat
 should be a zero length file. If you are getting the above error from
 rsync then you will probably find that out.dat contains some text or
 data. Look at the contents and try to work out what is producing it.
 The most common cause is incorrectly configured shell startup scripts
 (such as .cshrc or .profile) that contain output statements for non-
 interactive logins.
 If you are having trouble debugging filter patterns, then try
 specifying the -vv option. At this level of verbosity rsync will show
 why each individual file is included or excluded.

EXIT VALUES

 o 0 - Success
 o 1 - Syntax or usage error
 o 2 - Protocol incompatibility
 o 3 - Errors selecting input/output files, dirs
 o
 o 4 - Requested action not supported. Either:
 an attempt was made to manipulate 64-bit files on a
 platform that cannot support them
 o an option was specified that is supported by the client
 and not by the server
 o 5 - Error starting client-server protocol
 o 6 - Daemon unable to append to log-file
 o 10 - Error in socket I/O
 o 11 - Error in file I/O
 o 12 - Error in rsync protocol data stream
 o 13 - Errors with program diagnostics
 o 14 - Error in IPC code
 o 20 - Received SIGUSR1 or SIGINT
 o 21 - Some error returned by waitpid()
 o 22 - Error allocating core memory buffers
 o 23 - Partial transfer due to error
 o 24 - Partial transfer due to vanished source files
 o 25 - The --max-delete limit stopped deletions
 o 30 - Timeout in data send/receive
 o 35 - Timeout waiting for daemon connection

ENVIRONMENT VARIABLES

 CVSIGNORE
 The CVSIGNORE environment variable supplements any ignore
 patterns in .cvsignore files. See the --cvs-exclude option for
 more details.
 RSYNC_ICONV
 Specify a default --iconv setting using this environment
 variable. First supported in 3.0.0.
 RSYNC_OLD_ARGS
 Specify a "1" if you want the --old-args option to be enabled by
 default, a "2" (or more) if you want it to be enabled in the
 repeated-option state, or a "0" to make sure that it is disabled
 by default. When this environment variable is set to a non-zero
 value, it supersedes the RSYNC_PROTECT_ARGS variable.
 This variable is ignored if --old-args, --no-old-args, or
 --secluded-args is specified on the command line.
 First supported in 3.2.4.
 RSYNC_PROTECT_ARGS
 Specify a non-zero numeric value if you want the --secluded-args
 option to be enabled by default, or a zero value to make sure
 that it is disabled by default.
 This variable is ignored if --secluded-args, --no-secluded-args,
 or --old-args is specified on the command line.
 First supported in 3.1.0. Starting in 3.2.4, this variable is
 ignored if RSYNC_OLD_ARGS is set to a non-zero value.
 RSYNC_RSH
 This environment variable allows you to override the default
 shell used as the transport for rsync. Command line options are
 permitted after the command name, just as in the --rsh (-e)
 option.
 RSYNC_PROXY
 This environment variable allows you to redirect your rsync
 client to use a web proxy when connecting to an rsync daemon.
 You should set RSYNC_PROXY to a hostname:port pair.
 RSYNC_PASSWORD
 This environment variable allows you to set the password for an
 rsync daemon connection, which avoids the password prompt. Note
 that this does not supply a password to a remote shell transport
 such as ssh (consult its documentation for how to do that).
 USER or LOGNAME
 The USER or LOGNAME environment variables are used to determine
 the default username sent to an rsync daemon. If neither is
 set, the username defaults to "nobody". If both are set, USER
 takes precedence.
 RSYNC_PARTIAL_DIR
 This environment variable specifies the directory to use for a
 --partial transfer without implying that partial transfers be
 enabled. See the --partial-dir option for full details.
 RSYNC_COMPRESS_LIST
 This environment variable allows you to customize the
 negotiation of the compression algorithm by specifying an
 alternate order or a reduced list of names. Use the command
 rsync --version to see the available compression names. See the
 --compress option for full details.
 RSYNC_CHECKSUM_LIST
 This environment variable allows you to customize the
 negotiation of the checksum algorithm by specifying an alternate
 order or a reduced list of names. Use the command
 rsync --version to see the available checksum names. See the
 --checksum-choice option for full details.
 RSYNC_MAX_ALLOC
 This environment variable sets an allocation maximum as if you
 had used the --max-alloc option.
 RSYNC_PORT
 This environment variable is not read by rsync, but is instead
 set in its sub-environment when rsync is running the remote
 shell in combination with a daemon connection. This allows a
 script such as rsync-ssl to be able to know the port number that
 the user specified on the command line.
 HOME This environment variable is used to find the user's default
 .cvsignore file.
 RSYNC_CONNECT_PROG
 This environment variable is mainly used in debug setups to set
 the program to use when making a daemon connection. See
 CONNECTING TO AN RSYNC DAEMON for full details.
 RSYNC_SHELL
 This environment variable is mainly used in debug setups to set
 the program to use to run the program specified by
 RSYNC_CONNECT_PROG. See CONNECTING TO AN RSYNC DAEMON for full
 details.

FILES

 /etc/rsyncd.conf or rsyncd.conf

SEE ALSO

 rsync(1)

BUGS

 o Times are transferred as *nix time_t values.
 o When transferring to FAT filesystems rsync may re-sync
 unmodified files. See the comments on the --modify-window
 option.
 o File permissions, devices, etc. are transferred as native
 numerical values.
 o See also the comments on the --delete option.
 Please report bugs! See the web site at <https://rsync.samba.org/ >.

VERSION

 This manpage is current for version 3.3.0 of rsync.

INTERNAL OPTIONS

 The options --server and --sender are used internally by rsync, and
 should never be typed by a user under normal circumstances. Some
 awareness of these options may be needed in certain scenarios, such as
 when setting up a login that can only run an rsync command. For
 instance, the support directory of the rsync distribution has an
 example script named rrsync (for restricted rsync) that can be used
 with a restricted ssh login.

CREDITS

 Rsync is distributed under the GNU General Public License. See the
 file COPYING for details.
 An rsync web site is available at <https://rsync.samba.org/ >. The site
 includes an FAQ-O-Matic which may cover questions unanswered by this
 manual page.
 The rsync github project is <https://github.com/WayneD/rsync >.
 We would be delighted to hear from you if you like this program.
 Please contact the mailing-list at rsync@lists.samba.org
 <mailto:rsync@lists.samba.org>.
 This program uses the excellent zlib compression library written by
 Jean-loup Gailly and Mark Adler.

THANKS

 Special thanks go out to: John Van Essen, Matt McCutchen, Wesley W.
 Terpstra, David Dykstra, Jos Backus, Sebastian Krahmer, Martin Pool,
 and our gone-but-not-forgotten compadre, J.W. Schultz.
 Thanks also to Richard Brent, Brendan Mackay, Bill Waite, Stephen
 Rothwell and David Bell. I've probably missed some people, my
 apologies if I have.

AUTHOR

 Rsync was originally written by Andrew Tridgell and Paul Mackerras.
 Many people have later contributed to it. It is currently maintained by
 Wayne Davison.
 Mailing lists for support and development are available at
 <https://lists.samba.org/ +>.
rsync 3.3.0 6 Apr 2024 rsync(1)

rsync 3.3.0 - Generated Fri Apr 19 07:33:24 CDT 2024
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