Trash Filing System

Question

This is a script (function) to be added to a bashrc. The purpose is to not actually remove files, but rather to send them to a trash folder for safe keeping. I was tired of deleting important files. Because files may have the same name, I chose to create subdirectories with the date and file name on them, for easy access and to prevent conflicts.

Thoughts? Improvements I could make? This is my first BASH script function, and I'd love to make it a standard part of my computers, so I want to make it good first!

function rm { 
 PREFIX="~/.Trash";
 for FILE in "$@" ; do 
 STARDATE=`date +%Y%m%d-%H%M`;
 PLACE="${STARDATE}-${FILE}" ; 
 mkdir -p "${PREFIX}/${PLACE}"; 
 mv $FILE $PREFIX/$PLACE/$FILE ; 
 echo "${FILE} moved to ${PREFIX}/${PLACE}" ; 
 done
}

• Dagg: Does this work if the file name has spaces in it? I suspect it doesn't, since $PREFIX/$PLACE/$FILE is not quoted. Also, why do you use ${foo} instead of just $foo?
• 200_success: What operating system? Have you also considered LVM snapshots (Linux) or ZFS snapshots (BSD/Solaris) or Time Machine backups (Mac OS)?

Answer 1

Interesting idea! I propose to rewrite the script this way:

rm() { 
 TRASH=~/.Trash
 for FILE; do
 DATE=$(date +%Y%m%d-%H%M)
 TARGETDIR="$TRASH/$DATE-$FILE"
 mkdir -p "$TARGETDIR"
 mv -v "$FILE" "$TARGETDIR/"
 done
}

What I changed and why:

• for i; do is equivalent to for i in "$@"; do but shorter
• In PREFIX="~/.Trash", the ~ does NOT expand to your home directory, so I believe this is a bug. And since there's nothing to quote in .Trash either, you can just write PREFIX=~/.Trash without any quoting
• Instead of an echo after the mv, you can use the -v flag to make mv more verbose and speak for itself
• Correctly quoted everywhere it's necessary
• Changed the deprecated `cmd` style command substitution to the new recommended $(cmd) style
• Renamed variables to be more intuitive, though I know this is subjective:
  • PREFIX to TRASH, to be more specific and clear
  • STARDATE to DATE, because I don't know what is "STAR" and DATE alone is already pretty clear
  • combined PREFIX + PLACE to TARGETDIR to reduce duplication
• Changed function rm { to rm() {, because this seems to be the preferred way to declare functions in bash
• Removed all the trailing ;, you don't need them
• Use $VARNAME instead of ${VARNAME}, because I find that easier to read, but do as you like

Personally I would rename rm() to trash(), because most of the time I certainly don't want to backup everything, especially when deleting directories. trash also seems intuitive.

By the way, this is a great site to check your Bash scripts for common mistakes:

http://www.shellcheck.net/#

Answer 2

You should realize that this is not a drop-in replacement for /bin/rm. For example, this function won't handle options such as -f correctly.

You double-quoted several variable expansions, but you must make it a religious habit to always double-quote all such expansions. Otherwise, special characters in filenames will break your script in nasty ways.

Error handling is poor. You'll echo a confirmation even when mv fails. Therefore, you should join commands nontrivial with semicolons, but with &&. Also, errors should go to standard error instead of standard out, so use echo "..." >&2.