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
/src/cmd/grep
/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.