GREP(1) (Essential Utilities) GREP(1)
NAME
grep - search a file for a pattern
SYNOPSIS
grep [options] limited regular expression [file ...]
DESCRIPTION
grep searches files for a pattern and prints all lines that
contain that pattern. grep uses limited regular expressions
(expressions that have string values that use a subset of
the possible alphanumeric and special characters) like those
used with ed (1) to match the patterns. It uses a compact
non-deterministic algorithm.
Be careful using the characters $, *, [, ^, |, (, ), and \
in the limited regular expression because they are also
meaningful to the shell. It is safest to enclose the entire
limited regular expression in single quotes '...'.
If no files are specified, grep assumes standard input.
Normally, each line found is copied to standard output. The
file name is printed before each line found if there is more
than one input file.
Command line options are:
-b Precede each line by the block number on which it was
found. This can be useful in locating block numbers
by context (first block is 0).
-c Print only a count of the lines that contain the
pattern.
-i Ignore upper/lower case distinction during
comparisons.
-l Print the names of files with matching lines once,
separated by new-lines. Does not repeat the names of
files when the pattern is found more than once.
-n Precede each line by its line number in the file
(first line is 1).
-s Suppress error messages about nonexistent or
unreadable files
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GREP(1) (Essential Utilities) GREP(1)
-v Print all lines except those that contain the pattern.
SEE ALSO
ed(1), egrep(1), fgrep(1), sed(1), sh(1).
DIAGNOSTICS
Exit status is 0 if any matches are found, 1 if none, 2 for
syntax errors or inaccessible files (even if matches were
found).
BUGS
Lines are limited to BUFSIZ characters; longer lines are
truncated. BUFSIZ is defined in /usr/include/stdio.h.
If there is a line with embedded nulls, grep will only match
up to the first null; if it matches, it will print the
entire line.
Page 2 May 1989