Usage: grep [OPTION]... PATTERN [FILE] ... Search for PATTERN in each FILE or standard input. Example: grep -i 'hello world' menu.h main.c

Regexp selection and interpretation: -E, --extended-regexp PATTERN is an extended regular expression -F, --fixed-strings PATTERN is a set of newline-separated strings -G, --basic-regexp PATTERN is a basic regular expression -P, --perl-regexp PATTERN is a Perl regular expression -e, --regexp=PATTERN use PATTERN as a regular expression -f, --file=FILE obtain PATTERN from FILE -i, --ignore-case ignore case distinctions -w, --word-regexp force PATTERN to match only whole words -x, --line-regexp force PATTERN to 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 print version information and exit --help display this help and exit --mmap use memory-mapped input if possible