grep

Usage: grep [OPTION]... PATTERNS [FILE]...
Search for PATTERNS in each FILE.
Example: grep -i 'hello world' menu.h main.c
PATTERNS can contain multiple patterns separated by newlines.
Pattern selection and interpretation:
 -E, --extended-regexp PATTERNS are extended regular expressions
 -F, --fixed-strings PATTERNS are strings
 -G, --basic-regexp PATTERNS are basic regular expressions
 -P, --perl-regexp PATTERNS are Perl regular expressions
 -e, --regexp=PATTERNS use PATTERNS for matching
 -f, --file=FILE take PATTERNS from FILE
 -i, --ignore-case ignore case distinctions in patterns and data
 --no-ignore-case do not ignore case distinctions (default)
 -w, --word-regexp match only whole words
 -x, --line-regexp match only whole lines
 -z, --null-data a data line ends in 0 byte, not newline
Miscellaneous:
 -s, --no-messages suppress error messages
 -v, --invert-match select non-matching lines
 -V, --version display version information and exit
 --help display this help text and exit
Output control:
 -m, --max-count=NUM stop after NUM selected lines
 -b, --byte-offset print the byte offset with output lines
 -n, --line-number print line number with output lines
 --line-buffered flush output on every line
 -H, --with-filename print file name with output lines
 -h, --no-filename suppress the file name prefix on output
 --label=LABEL use LABEL as the standard input file name prefix
 -o, --only-matching show only nonempty parts of lines that match
 -q, --quiet, --silent suppress all normal output
 --binary-files=TYPE assume that binary files are TYPE;
 TYPE is 'binary', 'text', or 'without-match'
 -a, --text equivalent to --binary-files=text
 -I equivalent to --binary-files=without-match
 -d, --directories=ACTION how to handle directories;
 ACTION is 'read', 'recurse', or 'skip'
 -D, --devices=ACTION how to handle devices, FIFOs and sockets;
 ACTION is 'read' or 'skip'
 -r, --recursive like --directories=recurse
 -R, --dereference-recursive likewise, but follow all symlinks
 --include=GLOB search only files that match GLOB (a file pattern)
 --exclude=GLOB skip files that match GLOB
 --exclude-from=FILE skip files that match any file pattern from FILE
 --exclude-dir=GLOB skip directories that match GLOB
 -L, --files-without-match print only names of FILEs with no selected lines
 -l, --files-with-matches print only names of FILEs with selected lines
 -c, --count print only a count of selected lines per FILE
 -T, --initial-tab make tabs line up (if needed)
 -Z, --null print 0 byte after FILE name
Context control:
 -B, --before-context=NUM print NUM lines of leading context
 -A, --after-context=NUM print NUM lines of trailing context
 -C, --context=NUM print NUM lines of output context
 -NUM same as --context=NUM
 --group-separator=SEP print SEP on line between matches with context
 --no-group-separator do not print separator for matches with context
 --color[=WHEN],
 --colour[=WHEN] use markers to highlight the matching strings;
 WHEN is 'always', 'never', or 'auto'
 -U, --binary do not strip CR characters at EOL (MSDOS/Windows)
When FILE is '-', read standard input. With no FILE, read '.' if
recursive, '-' otherwise. With fewer than two FILEs, assume -h.
Exit status is 0 if any line is selected, 1 otherwise;
if any error occurs and -q is not given, the exit status is 2.
Report bugs to: bug-grep@gnu.org
GNU grep home page: <https://www.gnu.org/software/grep/>
General help using GNU software: <https://www.gnu.org/gethelp/>