EGREP(1) User Commands EGREP(1)


egrep - search a file for a pattern using full regular expressions


/usr/bin/egrep [-bcHhilnqsv] -e pattern_list [file...]

/usr/bin/egrep [-bcHhilnqsv] -f file [file...]

/usr/bin/egrep [-bcHhilnqsv] pattern [file...]

/usr/xpg4/bin/egrep [-bcHhilnqsvx] -e pattern_list [-f file]

/usr/xpg4/bin/egrep [-bcHhilnqsvx] [-e pattern_list] -f file

/usr/xpg4/bin/egrep [-bcHhilnqsvx] pattern [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.

The /usr/bin/egrep utility accepts full regular expressions as described
on the regexp(5) manual page, except for \( and \), \( and \), \{ and \},
\< and \>, and \n, 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.

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

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).

Print only a count of the lines that contain the

-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.

Precedes each line by the name of the file containing
the matching line.

Suppress printing of filenames when searching multiple

Ignore upper/lower case distinction during

Print the names of files with matching lines once,
separated by NEWLINEs. Does not repeat the names of
files when the pattern is found more than once.

Precede each line by its line number in the file
(first line is 1).

Quiet. Does not write anything to the standard output,
regardless of matching lines. Exits with zero status
if an input line is selected.

Legacy equivalent of -q.

Print all lines except those that contain the pattern.

The following options are supported for /usr/xpg4/bin/egrep only:

Consider only input lines that use all characters in the line to
match an entire fixed string or regular expression to be matching


The following operands are supported:

A path name of a file to be searched for the patterns. If no file
operands are specified, the standard input is used.

Specify a pattern to be used during the search for input.

Specify one or more patterns to be used during the search for
input. This operand is treated as if it were specified as


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_MESSAGES,


The following exit values are returned:

If any matches are found.

If no matches are found.

For syntax errors or inaccessible files (even if matches were


See attributes(5) for descriptions of the following attributes:


|CSI | Not Enabled |


|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 trade-offs.

Lines are limited only by the size of the available virtual memory.

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.

May 3, 2013 EGREP(1)