NAME

	grep, g – search a file for a pattern

SYNOPSIS

	grep [ option ... ] pattern [ file ... ] g [ option ... ] pattern [ file ... ]

DESCRIPTION

Grep searches the input files (standard input default) for lines that match the pattern, a regular expression as defined in regexp(7) with the addition of a newline character as an alternative (substitute for |) with lowest precedence. Normally, each line matching the pattern is ‘selected’, and each selected line is copied to the standard output. The options are −c    Print only a count of matching lines. −h    Do not print file name tags (headers) with output lines. −e    The following argument is taken as a pattern. This option makes it easy to specify patterns that might confuse argument parsing, such as −n. −i    Ignore alphabetic case distinctions. The implementation folds into lower case all letters in the pattern and input before interpretation. Matched lines are printed in their original form. −l    (ell) Print the names of files with selected lines; don’t print the lines. −L    Print the names of files with no selected lines; the converse of −l. −n    Mark each printed line with its line number counted in its file. −s    Produce no output, but return status. −v    Reverse: print lines that do not match the pattern. −f    The pattern argument is the name of a file containing regular expressions one per line. −b    Don’t buffer the output: write each output line as soon as it is discovered. Output lines are tagged by file name when there is more than one input file. (To force this tagging, include /dev/null as a file name argument.) Care should be taken when using the shell metacharacters $*[^|()=\ and newline in pattern; it is safest to enclose the entire expression in single quotes '...'. An expression starting with ’*’ will treat the rest of the expression as literal characters. G invokes grep with −n and forces tagging of output lines by file name. If no files are listed, it searches all files matching *.C *.b *.c *.h *.m *.cc *.java *.cgi *.pl *.py *.tex *.ms

SOURCE

	/usr/local/plan9/src/cmd/grep /usr/local/plan9/bin/g

SEE ALSO

	ed(1), awk(1), sed(1), sam(1), regexp(7)

DIAGNOSTICS

	Exit status is null if any lines are selected, or non-null when no lines are selected or an error occurs.