Получение дополнительной информации

man –s N intro

#man grep

Name
grep - search a file for a pattern
Synopsis
/usr/bin/grep [-bchilnsvw] limited-regular-expression [filename...]
/usr/xpg4/bin/grep [-E | -F] [-c | -l | -q] [-bhinsvwx] -e pattern_
list... [-f pattern_file]... [file...]
/usr/xpg4/bin/grep [-E | -F] [-c | -l | -q] [-bhinsvwx] [-e pattern_
list...] -f pattern_file... [file...]
/usr/xpg4/bin/grep [-E | -F] [-c | -l | -q] [-bhinsvwx] pattern
[file...]
Description
The grep utility searches text files for a pattern and prints all
lines that contain that pattern. It uses a compact non-deterministic
algorithm.
Be careful using the characters $, *, [, ^, |, (, ), and \ in the
pattern_list because they are also meaningful to the shell. It is
safest to enclose the entire pattern_list 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.
/usr/bin/grep
The /usr/bin/grep utility uses limited regular expressions like those
described on the regexp(5) manual page to match the patterns.
/usr/xpg4/bin/grep
The options -E and -F affect the way /usr/xpg4/bin/grep interprets
pattern_list. If -E is specified, /usr/xpg4/bin/grep interprets
pattern_list as a full regular expression (see -E for description). If
-F is specified, grep interprets pattern_list as a fixed string. If
neither are specified, grep interprets pattern_list as a basic regular
expression as described on regex(5) manual page.

Options
The following options are supported for both /usr/bin/grep and /usr/
xpg4/bin/grep:
-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.
-h
Prevents the name of the file containing the matching line from being
appended to that line. Used when searching multiple files.
-i
Large File Behavior

See largefile(5) for the description of the behavior of grep when
encountering files greater than or equal to 2 Gbyte ( 2 **31 bytes).

Examples
Example 1: Finding all uses of a word
To find all uses of the word "Posix" (in any case) in the file text.
mm, and write with line numbers:
example% /usr/bin/grep -i -n posix text.mm
Example 2: Finding all empty lines
To find all empty lines in the standard input:
example% /usr/bin/grep ^$
or
example% /usr/bin/grep -v .
Example 3: Finding lines containing strings
Both of the following commands print all lines containing strings abc
or def or both:
example% /usr/xpg4/bin/grep -E `abc def’
example% /usr/xpg4/bin/grep -F `abc def’
Example 4: Finding lines with matching strings
Both of the following commands print all lines matching exactly abc or
def:
example% /usr/xpg4/bin/grep -E `^abc$ ^def$’
example% /usr/xpg4/bin/grep -F -x `abc def’
Environment Variables
See environ(5) for descriptions of the following environment variables
that affect the execution of grep: LC_COLLATE, LC_CTYPE, LC_MESSAGES,
and NLSPATH.
Exit Status
The following exit values are returned:
0
One or more matches were found.
1
No matches were found.
2
Syntax errors or inaccessible files (even if matches were found).
See Also
egrep(1) , fgrep(1) , sed(1) , sh(1) , attributes(5) , environ(5) ,
largefile(5) , regex(5) , regexp(5) , XPG4(5)
Notes
/usr/bin/grep
Lines are limited only by the size of the available virtual memory. 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.
/usr/xpg4/bin/grep
The results are unspecified if input files contain lines longer than
LINE_MAX bytes or contain binary data. LINE_MAX is defined in /usr/
include/limits.h.