GREP(1) General Commands Manual GREP(1)NAME
grep, egrep, fgrep - search a file for a pattern
SYNOPSIS
grep [ option ] ... expression [ file ] ...
egrep [ option ] ... [ expression ] [ file ] ...
fgrep [ option ] ... [ strings ] [ file ]
DESCRIPTION
Commands of the grep family search the input files (standard input default) for lines matching a pattern. Normally, each line found is
copied to the standard output; unless the -h flag is used, the file name is shown if there is more than one input file.
Grep patterns are limited regular expressions in the style of ed(1); it uses a compact nondeterministic algorithm. Egrep patterns are full
regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space. Fgrep patterns are fixed strings; it
is fast and compact.
The following options are recognized.
-v All lines but those matching are printed.
-c Only a count of matching lines is printed.
-l The names of files with matching lines are listed (once) separated by newlines.
-n Each line is preceded by its line number in the file.
-b Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by con-
text.
-s No output is produced, only status.
-h Do not print filename headers with output lines.
-y Lower case letters in the pattern will also match upper case letters in the input (grep only).
-e expression
Same as a simple expression argument, but useful when the expression begins with a -.
-f file
The regular expression (egrep) or string list (fgrep) is taken from the file.
-x (Exact) only lines matched in their entirety are printed (fgrep only).
Care should be taken when using the characters $ * [ ^ | ? ' " ( ) and in the expression as they are also meaningful to the Shell. It is
safest to enclose the entire expression argument in single quotes ' '.
Fgrep searches for lines that contain one of the (newline-separated) strings.
Egrep accepts extended regular expressions. In the following description `character' excludes newline:
A followed by a single character matches that character.
The character ^ ($) matches the beginning (end) of a line.
A . matches any character.
A single character not otherwise endowed with special meaning matches that character.
A string enclosed in brackets [] matches any single character from the string. Ranges of ASCII character codes may be abbreviated
as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as
a range indicator.
A regular expression followed by * (+, ?) matches a sequence of 0 or more (1 or more, 0 or 1) matches of the regular expression.
Two regular expressions concatenated match a match of the first followed by a match of the second.
Two regular expressions separated by | or newline match either a match for the first or a match for the second.
A regular expression enclosed in parentheses matches a match for the regular expression.
The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline.
SEE ALSO ed(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.
BUGS
Ideally there should be only one grep, but we don't know a single algorithm that spans a wide enough range of space-time tradeoffs.
Lines are limited to 256 characters; longer lines are truncated.
GREP(1)
Check Out this Related Man Page
egrep(1)egrep(1)NAME
egrep - search a file for a pattern using full regular expressions
SYNOPSIS
/usr/bin/egrep [-bchilnsv] [-e pattern_list] [-f file] [strings] [file...]
/usr/xpg4/bin/egrep [-bchilnsvx] [-e pattern_list] [-f file] [strings] [file...]
The egrep (expression grep) utility searches files for a pattern of characters and prints all lines that contain that pattern. egrep uses
full regular expressions (expressions that have string values that use the full set of alphanumeric and special characters) to match the
patterns. It uses a fast deterministic algorithm that sometimes needs exponential space.
If no files are specified, egrep assumes standard input. Normally, each line found is copied to the standard output. The file name is
printed before each line found if there is more than one input file.
/usr/bin/egrep
The /usr/bin/egrep utility accepts full regular expressions as described on the regexp(5) manual page, except for ( and ), ( and ), {
and }, < and >, and
, and with the addition of:
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 NEWLINE that match strings that are matched by any of the expressions.
4. A full regular expression that can be enclosed in parentheses ()for grouping.
Be careful using the characters $, *, [, ^, |, (, ), and in full regular expression, because they are also meaningful to the shell. It is
safest to enclose the entire full regular expression in single quotes '... '.
The order of precedence of operators is [], then *?+, then concatenation, then | and NEWLINE.
/usr/xpg4/bin/egrep
The /usr/xpg4/bin/egrep utility uses the regular expressions described in the EXTENDED REGULAR EXPRESSIONS section of the regex(5) manual
page.
The following options are supported for both /usr/bin/egrep and /usr/xpg4/bin/egrep:
-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.
-e pattern_list Search for a pattern_list (full regular expression that begins with a -).
-f file Take the list of full regular expressions from file.
-h Suppress printing of filenames when searching multiple files.
-i Ignore upper/lower case distinction during comparisons.
-l Print the names of files with matching lines once, separated by NEWLINEs. Does not repeat the names of files when the pat-
tern is found more than once.
-n Precede each line by its line number in the file (first line is 1).
-s Work silently, that is, display nothing except error messages. This is useful for checking the error status.
-v Print all lines except those that contain the pattern.
/usr/xpg4/bin/egrep
The following option is supported for /usr/xpg4/bin/egrep only:
-x Consider only input lines that use all characters in the line to match an entire fixed string or regular expression to be matching
lines.
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 is used.
/usr/bin/egrep
pattern Specify a pattern to be used during the search for input.
/usr/xpg4/bin/egrep
pattern Specify one or more patterns to be used during the search for input. This operand is treated as if it were specified as
-epattern_list.
USAGE
See largefile(5) for the description of the behavior of egrep when encountering files greater than or equal to 2 Gbyte ( 2**31 bytes).
See environ(5) for descriptions of the following environment variables that affect the execution of egrep: LC_COLLATE, LC_CTYPE, LC_MES-
SAGES, and NLSPATH.
The following exit values are returned:
0 If any matches are found.
1 If no matches are found.
2 For syntax errors or inaccessible files (even if matches were found).
See attributes(5) for descriptions of the following attributes:
/usr/bin/egrep
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
|CSI |Not Enabled |
+-----------------------------+-----------------------------+
/usr/xpg4/bin/egrep
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWxcu4 |
+-----------------------------+-----------------------------+
|CSI |Enabled |
+-----------------------------+-----------------------------+
fgrep(1), grep(1), sed(1), sh(1), attributes(5), environ(5), largefile(5), regex(5), regexp(5), XPG4(5)
Ideally there should be only one grep command, but there is not a single algorithm that spans a wide enough range of space-time tradeoffs.
Lines are limited only by the size of the available virtual memory.
/usr/xpg4/bin/egrep
The /usr/xpg4/bin/egrep utility is identical to /usr/xpg4/bin/grep -E (see grep(1)). Portable applications should use /usr/xpg4/bin/grep
-E.
23 May 2005 egrep(1)