grep(1)
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 com-
pact 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. Nor-
mally, 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 regu-
lar 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 Precedes 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 Prints only a count of the lines that contain the pat-
tern.
-h Prevents the name of the file containing the matching
line from being appended to that line. Used when
searching multiple files.
-i Ignores upper/lower case distinction during comparis-
ons.
-l Prints only the names of files with matching lines,
separated by NEWLINE characters. Does not repeat the
names of files when the pattern is found more than
once.
-n Precedes each line by its line number in the file
(first line is 1).
-s Suppresses error messages about nonexistent or unread-
able files.
-v Prints all lines except those that contain the pat-
tern.
-w Searches for the expression as a word as if surrounded
by \< and \>.
/usr/xpg4/bin/grep
The following options are supported for /usr/xpg4/bin/grep
only:
-e pattern_list
Specifies one or more patterns to be used during the
search for input. Patterns in pattern_list must be
separated by a NEWLINE character. A null pattern can
be specified by two adjacent newline characters in
pattern_list. Unless the -E or -F option is also
specified, each pattern is treated as a basic regular
expression. Multiple -e and -f options are accepted
by grep. All of the specified patterns are used when
matching lines, but the order of evaluation is
unspecified.
-E Matches using full regular expressions. Treats each
pattern specified as a full regular expression. If any
entire full regular expression pattern matches an
input line, the line will be matched. A null full reg-
ular expression matches every line. Each pattern is
interpreted as a full regular expression as described
on the regex(5) manual page, except for \( and \), and
including:
1. A full regular expression followed by + that
matches one or more occurrences of the full regular
expression.
2. A full regular expression followed by ? that
matches 0 or 1 occurrences of the full regular
expression.
3. Full regular expressions separated by | or by a
new-line that match strings that are matched by any
of the expressions.
4. A full regular expression that may be enclosed in
parentheses () for grouping.
The order of precedence of operators is [], then *?+,
then concatenation, then | and new-line.
-f pattern_file
Reads one or more patterns from the file named by the
path name pattern_file. Patterns in pattern_file are
terminated by a NEWLINE character. A null pattern can
be specified by an empty line in pattern_file. Unless
the -E or -F option is also specified, each pattern is
treated as a basic regular expression.
-F Matches using fixed strings. Treats each pattern
specified as a string instead of a regular expression.
If an input line contains any of the patterns as a
contiguous sequence of bytes, the line will be
matched. A null string matches every line. See
fgrep(1) for more information.
-q Quiet. Does not write anything to the standard output,
regardless of matching lines. Exits with zero status
if an input line is selected.
-x Considers only input lines that use all characters in
the line to match an entire fixed string or regular
expression to be matching lines.
OPERANDS
The following operands are supported:
file A path name of a file to be searched for the patterns.
If no file operands are specified, the standard input
will be used.
/usr/bin/grep
pattern
Specifies a pattern to be used during the search for
input.
/usr/xpg4/bin/grep
pattern
Specifies one or more patterns to be used during the
search for input. This operand is treated as if it
were specified as -e pattern_list.
USAGE
The -e pattern_list option has the same effect as the
pattern_list operand, but is useful when pattern_list begins
with the hyphen delimiter. It is also useful when it is more
convenient to provide multiple patterns as separate argu-
ments.
Multiple -e and -f options are accepted and grep will use
all of the patterns it is given while matching input text
lines. Notice that the order of evaluation is not specified.
If an implementation finds a null string as a pattern, it is
allowed to use that pattern first, matching every line, and
effectively ignore any other patterns.
The -q option provides a means of easily determining whether
or not a pattern (or string) exists in a group of files.
When searching several files, it provides a performance
improvement (because it can quit as soon as it finds the
first match) and requires less care by the user in choosing
the set of files to supply as arguments (because it will
exit zero if it finds a match even if grep detected an
access or read error on earlier file operands).
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
All of the following commands print all lines containing
strings abc or def or both:
example% /usr/xpg4/bin/grep 'abc
def'
example% /usr/xpg4/bin/grep -e 'abc
def'
example% /usr/xpg4/bin/grep -e 'abc' -e 'def'
example% /usr/xpg4/bin/grep -E 'abc|def'
example% /usr/xpg4/bin/grep -E -e 'abc|def'
example% /usr/xpg4/bin/grep -E -e 'abc' -e 'def'
example% /usr/xpg4/bin/grep -E 'abc
def'
example% /usr/xpg4/bin/grep -E -e 'abc
def'
example% /usr/xpg4/bin/grep -F -e 'abc' -e 'def'
example% /usr/xpg4/bin/grep -F 'abc
def'
example% /usr/xpg4/bin/grep -F -e '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: LANG, LC_ALL,
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).
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
/usr/bin/grep
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcsu |
|_____________________________|_____________________________|
| CSI | enabled |
|_____________________________|_____________________________|
/usr/xpg4/bin/grep
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWxcu4 |
|_____________________________|_____________________________|
| CSI | enabled |
|_____________________________|_____________________________|
| Interface Stability | Standard |
|_____________________________|_____________________________|
SEE ALSO
egrep(1), fgrep(1), sed(1), sh(1), attributes(5),
environ(5), largefile(5), regex(5), regexp(5), standards(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 the line matches, the
entire line will be printed.
/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.
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