GREP(1) GREP(1)
NAME
grep - search a file for a pattern
SYNOPSIS
grep [ option ... ] pattern [ file ... ]
DESCRIPTION
Grep searches the input files (standard input default) for
lines (with newlines excluded) that match the pattern, a
regular expression as defined in regexp(6). 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.
-i Ignore alphabetic case distinctions. The implementa-
tion 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.
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 '...'.
SOURCE
/sys/src/cmd/grep.c
SEE ALSO
ed(1), awk(1), sed(1), sam(1), regexp(6)
DIAGNOSTICS
Exit status is null if any lines are selected, or non-null
when no lines are selected or an error occurs.
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