673 lines
21 KiB
Plaintext
673 lines
21 KiB
Plaintext
\input texinfo @c -*-texinfo-*-
|
|
@c %**start of header
|
|
@setfilename grep.info
|
|
@settitle grep, print lines matching a pattern
|
|
@c %**end of header
|
|
|
|
@c This file has the new style title page commands.
|
|
@c Run `makeinfo' rather than `texinfo-format-buffer'.
|
|
|
|
@c smallbook
|
|
|
|
@c tex
|
|
@c \overfullrule=0pt
|
|
@c end tex
|
|
|
|
@include version.texi
|
|
|
|
@c Combine indices.
|
|
@syncodeindex ky cp
|
|
@syncodeindex pg cp
|
|
@syncodeindex tp cp
|
|
|
|
@defcodeindex op
|
|
@syncodeindex op fn
|
|
|
|
@ifinfo
|
|
@direntry
|
|
* grep: (grep). print lines matching a pattern.
|
|
@end direntry
|
|
This file documents @sc{grep}, a pattern matching engine.
|
|
|
|
|
|
Published by the Free Software Foundation,
|
|
59 Temple Place - Suite 330
|
|
Boston, MA 02111-1307, USA
|
|
|
|
Copyright (C) 1998 Free Software Foundation, Inc.
|
|
|
|
Permission is granted to make and distribute verbatim copies of
|
|
this manual provided the copyright notice and this permission notice
|
|
are preserved on all copies.
|
|
|
|
@ignore
|
|
Permission is granted to process this file through TeX and print the
|
|
results, provided the printed document carries copying permission
|
|
notice identical to this one except for the removal of this paragraph
|
|
(this paragraph not being relevant to the printed manual).
|
|
|
|
@end ignore
|
|
Permission is granted to copy and distribute modified versions of this
|
|
manual under the conditions for verbatim copying, provided that the entire
|
|
resulting derived work is distributed under the terms of a permission
|
|
notice identical to this one.
|
|
|
|
Permission is granted to copy and distribute translations of this manual
|
|
into another language, under the above conditions for modified versions,
|
|
except that this permission notice may be stated in a translation approved
|
|
by the Foundation.
|
|
@end ifinfo
|
|
|
|
@setchapternewpage off
|
|
|
|
@titlepage
|
|
@title grep, searching for a pattern
|
|
@subtitle version @value{VERSION}, @value{UPDATED}
|
|
@author Alain Magloire et al.
|
|
|
|
@page
|
|
@vskip 0pt plus 1filll
|
|
Copyright @copyright{} 1998 Free Software Foundation, Inc.
|
|
|
|
@sp 2
|
|
Published by the Free Software Foundation, @*
|
|
59 Temple Place - Suite 330, @*
|
|
Boston, MA 02111-1307, USA
|
|
|
|
Permission is granted to make and distribute verbatim copies of
|
|
this manual provided the copyright notice and this permission notice
|
|
are preserved on all copies.
|
|
|
|
Permission is granted to copy and distribute modified versions of this
|
|
manual under the conditions for verbatim copying, provided that the entire
|
|
resulting derived work is distributed under the terms of a permission
|
|
notice identical to this one.
|
|
|
|
Permission is granted to copy and distribute translations of this manual
|
|
into another language, under the above conditions for modified versions,
|
|
except that this permission notice may be stated in a translation approved
|
|
by the Foundation.
|
|
|
|
@end titlepage
|
|
@page
|
|
|
|
|
|
@node Top, Introduction, (dir), (dir)
|
|
@comment node-name, next, previous, up
|
|
|
|
@ifinfo
|
|
This document was produced for version @value{VERSION} of @sc{GNU} @sc{grep}.
|
|
@end ifinfo
|
|
|
|
@menu
|
|
* Introduction:: Introduction.
|
|
* Invoking:: Invoking @sc{grep}; description of options.
|
|
* Diagnostics:: Exit status returned by @sc{grep}.
|
|
* Grep Programs:: @sc{grep} programs.
|
|
* Regular Expressions:: Regular Expressions.
|
|
* Reporting Bugs:: Reporting Bugs.
|
|
* Concept Index:: A menu with all the topics in this manual.
|
|
* Index:: A menu with all @sc{grep} commands
|
|
and command-line options.
|
|
@end menu
|
|
|
|
|
|
@node Introduction, Invoking, Top, Top
|
|
@comment node-name, next, previous, up
|
|
@chapter Introduction
|
|
|
|
@cindex Searching for a pattern.
|
|
@sc{grep} searches the input files for lines containing a match to a given
|
|
pattern list. When it finds a match in a line, it copies the line to standard
|
|
output (by default), or does whatever other sort of output you have requested
|
|
with options. @sc{grep} expects to do the matching on text.
|
|
Since newline is also a separator for the list of patterns, there
|
|
is no way to match newline characters in a text.
|
|
|
|
@node Invoking, Diagnostics, Introduction, Top
|
|
@comment node-name, next, previous, up
|
|
@chapter Invoking @sc{grep}
|
|
|
|
@sc{grep} comes with a rich set of options from POSIX.2 and GNU extensions.
|
|
|
|
@table @samp
|
|
|
|
@item -c
|
|
@itemx --count
|
|
@opindex -c
|
|
@opindex -count
|
|
@cindex counting lines
|
|
Suppress normal output; instead print a count of matching
|
|
lines for each input file. With the @samp{-v}, @samp{--revert-match} option,
|
|
count non-matching lines.
|
|
|
|
@item -e @var{pattern}
|
|
@itemx --regexp=@var{pattern}
|
|
@opindex -e
|
|
@opindex --regexp=@var{pattern}
|
|
@cindex pattern list
|
|
Use @var{pattern} as the pattern; useful to protect patterns
|
|
beginning with a @samp{-}.
|
|
|
|
@item -f @var{file}
|
|
@itemx --file=@var{file}
|
|
@opindex -f
|
|
@opindex --file
|
|
@cindex pattern from file
|
|
Obtain patterns from @var{file}, one per line. The empty
|
|
file contains zero patterns, and therefore matches nothing.
|
|
|
|
@item -i
|
|
@itemx --ignore-case
|
|
@opindex -i
|
|
@opindex --ignore-case
|
|
@cindex case insensitive search
|
|
Ignore case distinctions in both the pattern and the input files.
|
|
|
|
@item -l
|
|
@itemx --files-with-matches
|
|
@opindex -l
|
|
@opindex --files-with-matches
|
|
@cindex names of matching files
|
|
Suppress normal output; instead print the name of each input
|
|
file from which output would normally have been printed.
|
|
The scanning of every file will stop on the first match.
|
|
|
|
@item -n
|
|
@itemx --line-number
|
|
@opindex -n
|
|
@opindex --line-number
|
|
@cindex line numbering
|
|
Prefix each line of output with the line number within its input file.
|
|
|
|
@item -q
|
|
@itemx --quiet
|
|
@itemx --silent
|
|
@opindex -q
|
|
@opindex --quiet
|
|
@opindex --silent
|
|
@cindex quiet, silent
|
|
Quiet; suppress normal output. The scanning of every file will stop on
|
|
the first match. Also see the @samp{-s} or @samp{--no-messages} option.
|
|
|
|
@item -s
|
|
@itemx --no-messages
|
|
@opindex -s
|
|
@opindex --no-messages
|
|
@cindex suppress error messages
|
|
Suppress error messages about nonexistent or unreadable files.
|
|
Portability note: unlike GNU @sc{grep}, BSD @sc{grep} does not comply
|
|
with POSIX.2, because BSD @sc{grep} lacks a @samp{-q} option and its
|
|
@samp{-s} option behaves like GNU @sc{grep}'s @samp{-q} option. Shell
|
|
scripts intended to be portable to BSD @sc{grep} should avoid both
|
|
@samp{-q} and @samp{-s} and should redirect
|
|
output to @file{/dev/null} instead.
|
|
|
|
@item -v
|
|
@itemx --revert-match
|
|
@opindex -v
|
|
@opindex --revert-match
|
|
@cindex revert matching
|
|
@cindex print non-matching lines
|
|
Invert the sense of matching, to select non-matching lines.
|
|
|
|
@item -x
|
|
@itemx --line-regexp
|
|
@opindex -x
|
|
@opindex --line-regexp
|
|
@cindex match the whole line
|
|
Select only those matches that exactly match the whole line.
|
|
|
|
@end table
|
|
|
|
@section GNU Extensions
|
|
|
|
@table @samp
|
|
|
|
@item -A @var{num}
|
|
@itemx --after-context=@var{num}
|
|
@opindex -A
|
|
@opindex --after-context
|
|
@cindex after context
|
|
@cindex context lines, after match
|
|
Print @var{num} lines of trailing context after matching lines.
|
|
|
|
@item -B @var{num}
|
|
@itemx --before-context=@var{num}
|
|
@opindex -B
|
|
@opindex --before-context
|
|
@cindex before context
|
|
@cindex context lines, before match
|
|
Print @var{num} lines of leading context before matching lines.
|
|
|
|
@item -C
|
|
@itemx --context@var{[=num]}
|
|
@opindex -C
|
|
@opindex --context
|
|
@cindex context
|
|
Print @var{num} lines (default 2) of output context.
|
|
|
|
|
|
@item -NUM
|
|
@opindex -NUM
|
|
Same as @samp{--context=@var{num}} lines of leading and trailing
|
|
context. However, grep will never print any given line more than once.
|
|
|
|
|
|
@item -V
|
|
@itemx --version
|
|
@opindex -V
|
|
@opindex --version
|
|
@cindex Version, printing
|
|
Print the version number of @sc{grep} to the standard output stream.
|
|
This version number should be included in all bug reports.
|
|
|
|
@item --help
|
|
@opindex --help
|
|
@cindex Usage summary, printing
|
|
Print a usage message briefly summarizing these command-line options
|
|
and the bug-reporting address, then exit.
|
|
|
|
@item -b
|
|
@itemx --byte-offset
|
|
@opindex -b
|
|
@opindex --byte-offset
|
|
@cindex byte offset
|
|
Print the byte offset within the input file before each line of output.
|
|
When @sc{grep} runs on MS-DOS or MS-Windows, the printed byte offsets
|
|
depend on whether the @samp{-u} (@samp{--unix-byte-offsets}) option is
|
|
used; see below.
|
|
|
|
@item -d @var{action}
|
|
@itemx --directories=@var{action}
|
|
@opindex -d
|
|
@opindex --directories
|
|
@cindex directory search
|
|
If an input file is a directory, use @var{action} to process it.
|
|
By default, @var{action} is @samp{read}, which means that directories are
|
|
read just as if they were ordinary files (some operating systems
|
|
and filesystems disallow this, and will cause @sc{grep} to print error
|
|
messages for every directory). If @var{action} is @samp{skip},
|
|
directories are silently skipped. If @var{action} is @samp{recurse},
|
|
@sc{grep} reads all files under each directory, recursively; this is
|
|
equivalent to the @samp{-r} option.
|
|
|
|
@item -h
|
|
@itemx --no-filename
|
|
@opindex -h
|
|
@opindex --no-filename
|
|
@cindex no filename prefix
|
|
Suppress the prefixing of filenames on output when multiple files are searched.
|
|
|
|
@item -L
|
|
@itemx --files-without-match
|
|
@opindex -L
|
|
@opindex --files-without-match
|
|
@cindex files which don't match
|
|
Suppress normal output; instead print the name of each input
|
|
file from which no output would normally have been printed.
|
|
The scanning of every file will stop on the first match.
|
|
|
|
@item -a
|
|
@itemx --text
|
|
@opindex -a
|
|
@opindex --text
|
|
@cindex suppress binary data
|
|
@cindex binary files
|
|
Do not suppress output lines that contain binary data.
|
|
Normally, if the first few bytes of a file indicate
|
|
that the file contains binary data, grep outputs only a
|
|
message saying that the file matches the pattern. This
|
|
option causes grep to act as if the file is a text
|
|
file, even if it would otherwise be treated as binary.
|
|
@emph{Warning:} the result might be binary garbage
|
|
printed to the terminal, which can have nasty
|
|
side-effects if the terminal driver interprets some of
|
|
it as commands.
|
|
|
|
@item -w
|
|
@itemx --word-regexp
|
|
@opindex -w
|
|
@opindex --word-regexp
|
|
@cindex matching whole words
|
|
Select only those lines containing matches that form
|
|
whole words. The test is that the matching substring
|
|
must either be at the beginning of the line, or preceded
|
|
by a non-word constituent character. Similarly,
|
|
it must be either at the end of the line or followed by
|
|
a non-word constituent character. Word-constituent
|
|
characters are letters, digits, and the underscore.
|
|
|
|
@item -r
|
|
@itemx --recursive
|
|
@opindex -r
|
|
@opindex --recursive
|
|
@cindex recursive search
|
|
@cindex searching directory trees
|
|
For each directory mentioned in the command line, read and process all
|
|
files in that directory, recursively. This is the same as the @samp{-d
|
|
recurse} option.
|
|
|
|
@item -y
|
|
@opindex -y
|
|
@cindex case insensitive search, obsolete option
|
|
Obsolete synonym for @samp{-i}.
|
|
|
|
@item -U
|
|
@itemx --binary
|
|
@opindex -U
|
|
@opindex --binary
|
|
@cindex DOS/Windows binary files
|
|
@cindex binary files, DOS/Windows
|
|
Treat the file(s) as binary. By default, under MS-DOS
|
|
and MS-Windows, @sc{grep} guesses the file type by looking
|
|
at the contents of the first 32KB read from the file.
|
|
If @sc{grep} decides the file is a text file, it strips the
|
|
CR characters from the original file contents (to make
|
|
regular expressions with @code{^} and @code{$} work correctly).
|
|
Specifying @samp{-U} overrules this guesswork, causing all
|
|
files to be read and passed to the matching mechanism
|
|
verbatim; if the file is a text file with CR/LF pairs
|
|
at the end of each line, this will cause some regular
|
|
expressions to fail. This option is only supported on
|
|
MS-DOS and MS-Windows.
|
|
|
|
@item -u
|
|
@itemx --unix-byte-offsets
|
|
@opindex -u
|
|
@opindex --unix-byte-offsets
|
|
@cindex DOS byte offsets
|
|
@cindex byte offsets, on DOS/Windows
|
|
Report Unix-style byte offsets. This switch causes
|
|
@sc{grep} to report byte offsets as if the file were Unix style
|
|
text file, i.e. the byte offsets ignore the CR characters which were
|
|
stripped off. This will produce results identical to running @sc{grep} on
|
|
a Unix machine. This option has no effect unless @samp{-b}
|
|
option is also used; it is only supported on MS-DOS and
|
|
MS-Windows.
|
|
|
|
@end table
|
|
|
|
Several additional options control which variant of the @sc{grep}
|
|
matching engine is used. @xref{Grep Programs}.
|
|
|
|
@sc{grep} uses the environment variable @var{LANG} to
|
|
provide internationalization support, if compiled with this feature.
|
|
|
|
@node Diagnostics, Grep Programs, Invoking, Top
|
|
@comment node-name, next, previous, up
|
|
@chapter Diagnostics
|
|
Normally, exit status is 0 if matches were found, and 1 if no matches
|
|
were found (the @samp{-v} option inverts the sense of the exit status).
|
|
Exit status is 2 if there were syntax errors in the pattern,
|
|
inaccessible input files, or other system errors.
|
|
|
|
@node Grep Programs, Regular Expressions, Diagnostics, Top
|
|
@comment node-name, next, previous, up
|
|
@chapter @sc{grep} programs
|
|
|
|
@sc{grep} searches the named input files (or standard input if no
|
|
files are named, or the file name @file{-} is given) for lines containing
|
|
a match to the given pattern. By default, @sc{grep} prints the matching lines.
|
|
There are three major variants of @sc{grep}, controlled by the following options.
|
|
|
|
@table @samp
|
|
|
|
@item -G
|
|
@itemx --basic-regexp
|
|
@opindex -G
|
|
@opindex --basic-regexp
|
|
@cindex matching basic regular expressions
|
|
Interpret pattern as a basic regular expression. This is the default.
|
|
|
|
@item -E
|
|
@item --extended-regexp
|
|
@opindex -E
|
|
@opindex --extended-regexp
|
|
@cindex matching extended regular expressions
|
|
Interpret pattern as an extended regular expression.
|
|
|
|
|
|
@item -F
|
|
@itemx --fixed-strings
|
|
@opindex -F
|
|
@opindex --fixed-strings
|
|
@cindex matching fixed strings
|
|
Interpret pattern as a list of fixed strings, separated
|
|
by newlines, any of which is to be matched.
|
|
|
|
@end table
|
|
|
|
In addition, two variant programs @sc{egrep} and @sc{fgrep} are available.
|
|
@sc{egrep} is similar (but not identical) to @samp{grep -E}, and
|
|
is compatible with the historical Unix @sc{egrep}. @sc{fgrep} is the
|
|
same as @samp{grep -F}.
|
|
|
|
@node Regular Expressions, Reporting Bugs, Grep Programs, Top
|
|
@comment node-name, next, previous, up
|
|
@chapter Regular Expressions
|
|
@cindex regular expressions
|
|
|
|
A @dfn{regular expression} is a pattern that describes a set of strings.
|
|
Regular expressions are constructed analogously to arithmetic expressions,
|
|
by using various operators to combine smaller expressions.
|
|
@sc{grep} understands two different versions of regular expression
|
|
syntax: ``basic'' and ``extended''. In GNU @sc{grep}, there is no
|
|
difference in available functionality using either syntax.
|
|
In other implementations, basic regular expressions are less powerful.
|
|
The following description applies to extended regular expressions;
|
|
differences for basic regular expressions are summarized afterwards.
|
|
|
|
The fundamental building blocks are the regular expressions that match
|
|
a single character. Most characters, including all letters and digits,
|
|
are regular expressions that match themselves. Any metacharacter
|
|
with special meaning may be quoted by preceding it with a backslash.
|
|
A list of characters enclosed by @samp{[} and @samp{]} matches any
|
|
single character in that list; if the first character of the list is the
|
|
caret @samp{^}, then it
|
|
matches any character @strong{not} in the list. For example, the regular
|
|
expression @samp{[0123456789]} matches any single digit.
|
|
A range of @sc{ascii} characters may be specified by giving the first
|
|
and last characters, separated by a hyphen. Finally, certain named
|
|
classes of characters are predefined. Their names are self explanatory,
|
|
and they are :
|
|
|
|
@cindex classes of characters
|
|
@cindex character classes
|
|
@table @samp
|
|
|
|
@item [:alnum:]
|
|
@opindex alnum
|
|
@cindex alphanumeric characters
|
|
Any of [:digit:] or [:alpha:]
|
|
|
|
@item [:alpha:]
|
|
@opindex alpha
|
|
@cindex alphabetic characters
|
|
Any local-specific or one of the @sc{ascii} letters:@*
|
|
@code{a b c d e f g h i j k l m n o p q r s t u v w x y z},@*
|
|
@code{A B C D E F G H I J K L M N O P Q R S T U V W X Y Z}.
|
|
|
|
@item [:cntrl:]
|
|
@opindex cntrl
|
|
@cindex control characters
|
|
Any of @code{BEL}, @code{BS}, @code{CR}, @code{FF}, @code{HT},
|
|
@code{NL}, or @code{VT}.
|
|
|
|
@item [:digit:]
|
|
@opindex digit
|
|
@cindex digit characters
|
|
@cindex numeric characters
|
|
Any one of @code{0 1 2 3 4 5 6 7 8 9}.
|
|
|
|
@item [:graph:]
|
|
@opindex graph
|
|
@cindex graphic characters
|
|
Anything that is not a @samp{[:alphanum:]} or @samp{[:punct:]}.
|
|
|
|
@item [:lower:]
|
|
@opindex lower
|
|
@cindex lower-case alphabetic characters
|
|
Any one of @code{a b c d e f g h i j k l m n o p q r s t u v w x y z}.
|
|
|
|
@item [:print:]
|
|
@opindex print
|
|
@cindex printable characters
|
|
Any character from the @samp{[:space:]} class, and any character that is
|
|
@strong{not} in the @samp{[:isgraph:]} class.
|
|
|
|
@item [:punct:]
|
|
@opindex punct
|
|
@cindex punctuation characters
|
|
Any one of @code{!@: " #% & ' ( ) ; < = > ?@: [ \ ] * + , - .@: / : ^ _ @{ | @}}.
|
|
|
|
|
|
@item [:space:]
|
|
@opindex space
|
|
@cindex space characters
|
|
@cindex whitespace characters
|
|
Any one of @code{CR FF HT NL VT SPACE}.
|
|
|
|
@item [:upper:]
|
|
@opindex upper
|
|
@cindex upper-case alphabetic characters
|
|
Any one of @code{A B C D E F G H I J K L M N O P Q R S T U V W X Y Z}.
|
|
|
|
@item [:xdigit:]
|
|
@opindex xdigit
|
|
@cindex xdigit class
|
|
@cindex hexadecimal digits
|
|
Any one of @code{a b c d e f A B C D E F 0 1 2 3 4 5 6 7 8 9}.
|
|
|
|
@end table
|
|
For example, @samp{[[:alnum:]]} means @samp{[0-9A-Za-z]}, except the latter
|
|
form is dependent upon the @sc{ascii} character encoding, whereas the
|
|
former is portable. (Note that the brackets in these class names are
|
|
part of the symbolic names, and must be included in addition to
|
|
the brackets delimiting the bracket list). Most metacharacters lose
|
|
their special meaning inside lists. To include a literal @samp{]}, place it
|
|
first in the list. Similarly, to include a literal @samp{^}, place it anywhere
|
|
but first. Finally, to include a literal @samp{-}, place it last.
|
|
|
|
The period @samp{.} matches any single character. The symbol @samp{\w}
|
|
is a synonym for @samp{[[:alnum:]]} and @samp{\W} is a synonym for
|
|
@samp{[^[:alnum]]}.
|
|
|
|
The caret @samp{^} and the dollar sign @samp{$} are metacharacters that
|
|
respectively match the empty string at the beginning and end
|
|
of a line. The symbols @samp{\<} and @samp{\>} respectively match the
|
|
empty string at the beginning and end of a word. The symbol
|
|
@samp{\b} matches the empty string at the edge of a word, and @samp{\B}
|
|
matches the empty string provided it's not at the edge of a word.
|
|
|
|
A regular expression may be followed by one of several
|
|
repetition operators:
|
|
|
|
|
|
@table @samp
|
|
|
|
@item ?
|
|
@opindex ?
|
|
@cindex question mark
|
|
@cindex match sub-expression at most once
|
|
The preceding item is optional and will be matched at most once.
|
|
|
|
@item *
|
|
@opindex *
|
|
@cindex asterisk
|
|
@cindex match sub-expression zero or more times
|
|
The preceding item will be matched zero or more times.
|
|
|
|
@item +
|
|
@opindex +
|
|
@cindex plus sign
|
|
The preceding item will be matched one or more times.
|
|
|
|
@item @{@var{n}@}
|
|
@opindex @{n@}
|
|
@cindex braces, one argument
|
|
@cindex match sub-expression n times
|
|
The preceding item is matched exactly @var{n} times.
|
|
|
|
@item @{@var{n},@}
|
|
@opindex @{n,@}
|
|
@cindex braces, second argument omitted
|
|
@cindex match sub-expression n or more times
|
|
The preceding item is matched n or more times.
|
|
|
|
@item @{,@var{m}@}
|
|
@opindex @{,m@}
|
|
@cindex braces, first argument omitted
|
|
@cindex match sub-expression at most m times
|
|
The preceding item is optional and is matched at most @var{m} times.
|
|
|
|
@item @{@var{n},@var{m}@}
|
|
@opindex @{n,m@}
|
|
@cindex braces, two arguments
|
|
The preceding item is matched at least @var{n} times, but not more than
|
|
@var{m} times.
|
|
|
|
@end table
|
|
|
|
Two regular expressions may be concatenated; the resulting regular
|
|
expression matches any string formed by concatenating two substrings
|
|
that respectively match the concatenated subexpressions.
|
|
|
|
Two regular expressions may be joined by the infix operator @samp{|}; the
|
|
resulting regular expression matches any string matching either
|
|
subexpression.
|
|
|
|
Repetition takes precedence over concatenation, which in turn
|
|
takes precedence over alternation. A whole subexpression may be
|
|
enclosed in parentheses to override these precedence rules.
|
|
|
|
The backreference @samp{\@var{n}}, where @var{n} is a single digit, matches the
|
|
substring previously matched by the @var{n}th parenthesized subexpression
|
|
of the regular expression.
|
|
|
|
@cindex basic regular expressions
|
|
In basic regular expressions the metacharacters @samp{?}, @samp{+},
|
|
@samp{@{}, @samp{|}, @samp{(}, and @samp{)} lose their special meaning;
|
|
instead use the backslashed versions @samp{\?}, @samp{\+}, @samp{\@{},
|
|
@samp{\|}, @samp{\(}, and @samp{\)}.
|
|
|
|
In @sc{egrep} the metacharacter @samp{@{} loses its special meaning;
|
|
instead use @samp{\@{}. This not true for @samp{grep -E}.
|
|
|
|
|
|
@node Reporting Bugs, Concept Index, Regular Expressions, Top
|
|
@comment node-name, next, previous, up
|
|
@chapter Reporting bugs
|
|
|
|
@cindex Bugs, reporting
|
|
Email bug reports to @email{bug-gnu-utils@@gnu.org}.
|
|
Be sure to include the word ``grep'' somewhere in the ``Subject:'' field.
|
|
|
|
Large repetition counts in the @samp{@{m,n@}} construct may cause
|
|
@sc{grep} to use lots of memory. In addition, certain other
|
|
obscure regular expressions require exponential time and
|
|
space, and may cause grep to run out of memory.
|
|
Backreferences are very slow, and may require exponential time.
|
|
|
|
@page
|
|
@node Concept Index , Index, Reporting Bugs, Top
|
|
@comment node-name, next, previous, up
|
|
@unnumbered Concept Index
|
|
|
|
This is a general index of all issues discussed in this manual, with the
|
|
exception of the @sc{grep} commands and command-line options.
|
|
|
|
@printindex cp
|
|
|
|
@page
|
|
@node Index, , Concept Index, Top
|
|
@unnumbered Index
|
|
|
|
This is an alphabetical list of all @sc{grep} commands and command-line
|
|
options.
|
|
|
|
@printindex fn
|
|
|
|
@contents
|
|
@bye
|