grep prints lines that contain a match for a pattern.
This manual is for version 2.22 of GNU Grep.
This manual is for grep, a pattern matching engine.
Copyright © 1999-2002, 2005, 2008-2015 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.
grep searches 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 produces whatever other sort of output you have requested with options.
Though grep expects to do the matching on text, it has no limits on input line length other than available memory, and it can match arbitrary characters within a line. If the final byte of an input file is not a newline, grep silently supplies one. Since newline is also a separator for the list of patterns, there is no way to match newline characters in a text.
The general synopsis of the grep command line is
grep options pattern input_file_names
There can be zero or more options. pattern will only be seen as such (and not as an input_file_name) if it wasn't already specified within options (by using the ‘-e pattern’ or ‘-f file’ options). There can be zero or more input_file_names.
grep comes with a rich set of options: some from POSIX and some being GNU extensions. Long option names are always a GNU extension, even for options that are from POSIX specifications. Options that are specified by POSIX, under their short names, are explicitly marked as such to facilitate POSIX-portable programming. A few option names are provided for compatibility with older or more exotic implementations.
Several additional options control which variant of the grep matching engine is used. See grep Programs.
-y is an obsolete synonym that is provided for compatibility.
(-i is specified by POSIX.)
while grep -m 1 PATTERN do echo xxxx done < FILE
But the following probably will not work because a pipe is not a regular file:
# This probably will not work. cat FILE | while grep -m 1 PATTERN do echo xxxx done
When grep stops after num matching lines,
it outputs any trailing context lines.
Since context does not include matching lines,
grep will stop when it encounters another matching line.
When the -c or --count option is also used,
grep does not output a count greater than num.
When the -v or --invert-match option is also used,
grep stops after outputting num non-matching lines.
When several prefix fields are to be output, the order is always file name, line number, and byte offset, regardless of the order in which these options were specified.
gzip -cd foo.gz | grep --label=foo -H something
Regardless of how these options are set, grep will never print any given line more than once. If the -o (--only-matching) option is specified, these options have no effect and a warning is given upon their use.
Here are some points about how grep chooses the separator to print between prefix fields and line content:
By default, type is ‘binary’, and grep normally outputs either a one-line message saying that a binary file matches, or no message if there is no match. When processing binary data, grep may treat non-text bytes as line terminators; for example, the pattern ‘.’ (period) might not match a null byte, as the null byte might be treated as a line terminator even without the -z (--null-data) option.
If type is ‘without-match’, grep assumes that a binary file does not match; this is equivalent to the -I option.
If type is ‘text’, grep processes a binary file as if it were text; this is equivalent to the -a option.
Warning: ‘--binary-files=text’ might output binary garbage,
which can have nasty side effects
if the output is a terminal and
if the terminal driver interprets some of it as commands.
\
to quote a wildcard or backslash character literally.
^
and $
work correctly).
Specifying -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 has no effect
on platforms other than MS-DOS and MS-Windows.
The behavior of grep is affected by the following environment variables.
The locale for category LC_
foo
is specified by examining the three environment variables
LC_ALL, LC_foo, and LANG,
in that order.
The first of these variables that is set specifies the locale.
For example, if LC_ALL is not set,
but LC_COLLATE is set to ‘pt_BR’,
then the Brazilian Portuguese locale is used
for the LC_COLLATE category.
As a special case for LC_MESSAGES only, the environment variable
LANGUAGE can contain a colon-separated list of languages that
overrides the three environment variables that ordinarily specify
the LC_MESSAGES category.
The ‘C’ locale is used if none of these environment variables are set,
if the locale catalog is not installed,
or if grep was not compiled
with national language support (NLS).
Many of the environment variables in the following list let you control highlighting using Select Graphic Rendition (SGR) commands interpreted by the terminal or terminal emulator. (See the section in the documentation of your text terminal for permitted values and their meanings as character attributes.) These substring values are integers in decimal representation and can be concatenated with semicolons. grep takes care of assembling the result into a complete SGR sequence (‘\33[’...‘m’). Common values to concatenate include ‘1’ for bold, ‘4’ for underline, ‘5’ for blink, ‘7’ for inverse, ‘39’ for default foreground color, ‘30’ to ‘37’ for foreground colors, ‘90’ to ‘97’ for 16-color mode foreground colors, ‘38;5;0’ to ‘38;5;255’ for 88-color and 256-color modes foreground colors, ‘49’ for default background color, ‘40’ to ‘47’ for background colors, ‘100’ to ‘107’ for 16-color mode background colors, and ‘48;5;0’ to ‘48;5;255’ for 88-color and 256-color modes background colors.
The two-letter names used in the GREP_COLORS environment variable
(and some of the others) refer to terminal “capabilities,” the ability
of a terminal to highlight text, or change its color, and so on.
These capabilities are stored in an online database and accessed by
the terminfo
library.
#! /bin/sh export PATH=/usr/bin exec grep --color=auto --devices=skip "$@"
terminfo
capabilities
that defaults to ‘ms=01;31:mc=01;31:sl=:cx=:fn=35:ln=32:bn=32:se=36’
with the ‘rv’ and ‘ne’ boolean capabilities omitted (i.e., false).
Supported capabilities are as follows.
sl=
cx=
rv
mt=01;31
ms=01;31
mc=01;31
fn=35
ln=32
bn=32
se=36
ne
back_color_erase
(bce
) boolean terminfo
capability does not apply,
when the chosen highlight colors do not affect the background,
or when EL is too slow or causes too much flicker.
The default is false (i.e., the capability is omitted).
Note that boolean capabilities have no ‘=’... part.
They are omitted (i.e., false) by default and become true when specified.
Normally the exit status is 0 if a line is selected, 1 if no lines were selected, and 2 if an error occurred. However, if the -q or --quiet or --silent option is used and a line is selected, the exit status is 0 even if an error occurred. Other grep implementations may exit with status greater than 2 on error.
grep searches the named input files for lines containing a match to the given pattern. By default, grep prints the matching lines. A file named - stands for standard input. If no input is specified, grep searches the working directory . if given a command-line option specifying recursion; otherwise, grep searches standard input. There are four major variants of grep, controlled by the following options.
In addition, two variant programs egrep and fgrep are available. egrep is the same as ‘grep -E’. fgrep is the same as ‘grep -F’. Direct invocation as either egrep or fgrep is deprecated, but is provided to allow historical applications that rely on them to run unmodified.
A 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. grep understands three different versions of regular expression syntax: “basic,” (BRE) “extended” (ERE) and “perl”. In GNU grep, there is no difference in available functionality between the basic and extended syntaxes. 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. Perl regular expressions give additional functionality, and are documented in the pcresyntax(3) and pcrepattern(3) manual pages, but may not be available on every system.
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 meta-character with special meaning may be quoted by preceding it with a backslash.
A regular expression may be followed by one of several repetition operators:
The empty regular expression matches the empty string. Two regular expressions may be concatenated; the resulting regular expression matches any string formed by concatenating two substrings that respectively match the concatenated expressions.
Two regular expressions may be joined by the infix operator ‘|’; the resulting regular expression matches any string matching either alternate expression.
Repetition takes precedence over concatenation, which in turn takes precedence over alternation. A whole expression may be enclosed in parentheses to override these precedence rules and form a subexpression. An unmatched ‘)’ matches just itself.
A bracket expression is a list of characters enclosed by ‘[’ and ‘]’. It matches any single character in that list; if the first character of the list is the caret ‘^’, then it matches any character not in the list. For example, the regular expression ‘[0123456789]’ matches any single digit.
Within a bracket expression, a range expression consists of two characters separated by a hyphen. It matches any single character that sorts between the two characters, inclusive. In the default C locale, the sorting sequence is the native character order; for example, ‘[a-d]’ is equivalent to ‘[abcd]’. In other locales, the sorting sequence is not specified, and ‘[a-d]’ might be equivalent to ‘[abcd]’ or to ‘[aBbCcDd]’, or it might fail to match any character, or the set of characters that it matches might even be erratic. To obtain the traditional interpretation of bracket expressions, you can use the ‘C’ locale by setting the LC_ALL environment variable to the value ‘C’.
Finally, certain named classes of characters are predefined within bracket expressions, as follows. Their interpretation depends on the LC_CTYPE locale; for example, ‘[[:alnum:]]’ means the character class of numbers and letters in the current locale.
0 1 2 3 4 5 6 7 8 9
.
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
.
! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
.
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
.
0 1 2 3 4 5 6 7 8 9 A B C D E F a b c d e f
.
If you mistakenly omit the outer brackets, and search for say, ‘[:upper:]’, GNU grep prints a diagnostic and exits with status 2, on the assumption that you did not intend to search for the nominally equivalent regular expression: ‘[:epru]’. Set the POSIXLY_CORRECT environment variable to disable this feature.
Most meta-characters lose their special meaning inside bracket expressions.
The ‘\’ character, when followed by certain ordinary characters, takes a special meaning:
For example, ‘\brat\b’ matches the separate word ‘rat’, ‘\Brat\B’ matches ‘crate’ but not ‘furry rat’.
The caret ‘^’ and the dollar sign ‘$’ are meta-characters that respectively match the empty string at the beginning and end of a line. They are termed anchors, since they force the match to be “anchored” to beginning or end of a line, respectively.
The back-reference ‘\n’, where n is a single digit, matches the substring previously matched by the nth parenthesized subexpression of the regular expression. For example, ‘(a)\1’ matches ‘aa’. When used with alternation, if the group does not participate in the match then the back-reference makes the whole match fail. For example, ‘a(.)|b\1’ will not match ‘ba’. When multiple regular expressions are given with -e or from a file (‘-f file’), back-references are local to each expression.
In basic regular expressions the meta-characters ‘?’, ‘+’, ‘{’, ‘|’, ‘(’, and ‘)’ lose their special meaning; instead use the backslashed versions ‘\?’, ‘\+’, ‘\{’, ‘\|’, ‘\(’, and ‘\)’.
Traditional egrep did not support the ‘{’ meta-character, and some egrep implementations support ‘\{’ instead, so portable scripts should avoid ‘{’ in ‘grep -E’ patterns and should use ‘[{]’ to match a literal ‘{’.
GNU grep -E attempts to support traditional usage by assuming that ‘{’ is not special if it would be the start of an invalid interval specification. For example, the command ‘grep -E '{1'’ searches for the two-character string ‘{1’ instead of reporting a syntax error in the regular expression. POSIX allows this behavior as an extension, but portable scripts should avoid it.
Here is an example command that invokes GNU grep:
grep -i 'hello.*world' menu.h main.c
This lists all lines in the files menu.h and main.c that contain the string ‘hello’ followed by the string ‘world’; this is because ‘.*’ matches zero or more characters within a line. See Regular Expressions. The -i option causes grep to ignore case, causing it to match the line ‘Hello, world!’, which it would not otherwise match. See Invoking, for more details about how to invoke grep.
Here are some common questions and answers about grep usage.
grep -l 'main' *.c
lists the names of all C files in the current directory whose contents mention ‘main’.
grep -r 'hello' /home/gigi
searches for ‘hello’ in all files under the /home/gigi directory. For more control over which files are searched, use find, grep, and xargs. For example, the following command searches only C files:
find /home/gigi -name '*.c' -print0 | xargs -0r grep -H 'hello'
This differs from the command:
grep -H 'hello' *.c
which merely looks for ‘hello’ in all files in the current directory whose names end in ‘.c’. The ‘find ...’ command line above is more similar to the command:
grep -rH --include='*.c' 'hello' /home/gigi
grep -e '--cut here--' *
searches for all lines matching ‘--cut here--’. Without -e, grep would attempt to parse ‘--cut here--’ as a list of options.
grep -w 'hello' *
searches only for instances of ‘hello’ that are entire words; it does not match ‘Othello’. For more control, use ‘\<’ and ‘\>’ to match the start and end of words. For example:
grep 'hello\>' *
searches only for words ending in ‘hello’, so it matches the word ‘Othello’.
grep -C 2 'hello' *
prints two lines of context around each matching line.
Append /dev/null:
grep 'eli' /etc/passwd /dev/null
gets you:
/etc/passwd:eli:x:2098:1000:Eli Smith:/home/eli:/bin/bash
Alternatively, use -H, which is a GNU extension:
grep -H 'eli' /etc/passwd
ps -ef | grep '[c]ron'
If the pattern had been written without the square brackets, it would have matched not only the ps output line for cron, but also the ps output line for grep. Note that on some platforms, ps limits the output to the width of the screen; grep does not have any limit on the length of a line except the available memory.
If grep listed all matching “lines” from a binary file, it would probably generate output that is not useful, and it might even muck up your display. So GNU grep suppresses output from files that appear to be binary files. To force GNU grep to output lines even from files that appear to be binary, use the -a or ‘--binary-files=text’ option. To eliminate the “Binary file matches” messages, use the -I or ‘--binary-files=without-match’ option.
‘grep -lv’ lists the names of all files containing one or more lines that do not match. To list the names of all files that contain no matching lines, use the -L or --files-without-match option.
grep 'paul' /etc/motd | grep 'franc,ois'
finds all lines that contain both ‘paul’ and ‘franc,ois’.
The grep command searches for lines that contain strings that match a pattern. Every line contains the empty string, so an empty pattern causes grep to find a match on each line. It is not the only such pattern: ‘^’, ‘$’, ‘.*’, and many other patterns cause grep to match every line.
To match empty lines, use the pattern ‘^$’. To match blank lines, use the pattern ‘^[[:blank:]]*$’. To match no lines at all, use the command ‘grep -f /dev/null’.
Use the special file name ‘-’:
cat /etc/passwd | grep 'alain' - /etc/motd
It can be done by using back-references; for example, a palindrome of 4 characters can be written with a BRE:
grep -w -e '\(.\)\(.\).\2\1' file
It matches the word “radar” or “civic.”
Guglielmo Bondioni proposed a single RE that finds all palindromes up to 19 characters long using 9 subexpressions and 9 back-references:
grep -E -e '^(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?).?\9\8\7\6\5\4\3\2\1$' file
Note this is done by using GNU ERE extensions; it might not be portable to other implementations of grep.
echo 'ba' | grep -E '(a)\1|b\1'
This gives no output, because the first alternate ‘(a)\1’ does not match, as there is no ‘aa’ in the input, so the ‘\1’ in the second alternate has nothing to refer back to, meaning it will never match anything. (The second alternate in this example can only match if the first alternate has matched—making the second one superfluous.)
Standard grep cannot do this, as it is fundamentally line-based.
Therefore, merely using the [:space:]
character class does not
match newlines in the way you might expect.
With the GNU grep option -z (--null-data), each input “line” is terminated by a null byte; see Other Options. Thus, you can match newlines in the input, but typically if there is a match the entire input is output, so this usage is often combined with output-suppressing options like -q, e.g.:
printf 'foo\nbar\n' | grep -z -q 'foo[[:space:]]\+bar'
If this does not suffice, you can transform the input before giving it to grep, or turn to awk, sed, perl, or many other utilities that are designed to operate across lines.
The name grep comes from the way line editing was done on Unix. For example, ed uses the following syntax to print a list of matching lines on the screen:
global/regular expression/print g/re/p
fgrep stands for Fixed grep; egrep stands for Extended grep.
Bug reports can be found at the GNU bug report logs for grep. If you find a bug not listed there, please email it to bug-grep@gnu.org to create a new bug report.
Large repetition counts in the ‘{n,m}’ construct may cause 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.
Back-references are very slow, and may require exponential time.
GNU grep is licensed under the GNU GPL, which makes it free software.
The “free” in “free software” refers to liberty, not price. As some GNU project advocates like to point out, think of “free speech” rather than “free beer”. In short, you have the right (freedom) to run and change grep and distribute it to other people, and—if you want—charge money for doing either. The important restriction is that you have to grant your recipients the same rights and impose the same restrictions.
This general method of licensing software is sometimes called open source. The GNU project prefers the term “free software” for reasons outlined at http://www.gnu.org/philosophy/open-source-misses-the-point.html.
This manual is free documentation in the same sense. The documentation license is included below. The license for the program is available with the source code, or at http://www.gnu.org/licenses/gpl.html.
Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. http://fsf.org/ Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
The purpose of this License is to make a manual, textbook, or other functional and useful document free in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.
This License is a kind of “copyleft”, which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.
We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.
This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The “Document”, below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as “you”. You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law.
A “Modified Version” of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.
A “Secondary Section” is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.
The “Invariant Sections” are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none.
The “Cover Texts” are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words.
A “Transparent” copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not “Transparent” is called “Opaque”.
Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.
The “Title Page” means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, “Title Page” means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text.
The “publisher” means any person or entity that distributes copies of the Document to the public.
A section “Entitled XYZ” means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as “Acknowledgements”, “Dedications”, “Endorsements”, or “History”.) To “Preserve the Title” of such a section when you modify the Document means that it remains a section “Entitled XYZ” according to this definition.
The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.
You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.
You may also lend copies, under the same conditions stated above, and you may publicly display copies.
If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.
If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.
If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.
It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.
You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:
If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.
You may add a section Entitled “Endorsements”, provided it contains nothing but endorsements of your Modified Version by various parties—for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.
You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.
The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.
You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.
The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.
In the combination, you must combine any sections Entitled “History” in the various original documents, forming one section Entitled “History”; likewise combine any sections Entitled “Acknowledgements”, and any sections Entitled “Dedications”. You must delete all sections Entitled “Endorsements.”
You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.
You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.
A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an “aggregate” if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.
If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.
Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.
If a section in the Document is Entitled “Acknowledgements”, “Dedications”, or “History”, the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.
You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License.
However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.
Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.
Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, receipt of a copy of some or all of the same material does not give you any rights to use it.
The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.
Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License “or any later version” applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. If the Document specifies that a proxy can decide which future versions of this License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Document.
“Massive Multiauthor Collaboration Site” (or “MMC Site”) means any World Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works. A public wiki that anybody can edit is an example of such a server. A “Massive Multiauthor Collaboration” (or “MMC”) contained in the site means any set of copyrightable works thus published on the MMC site.
“CC-BY-SA” means the Creative Commons Attribution-Share Alike 3.0 license published by Creative Commons Corporation, a not-for-profit corporation with a principal place of business in San Francisco, California, as well as future copyleft versions of that license published by that same organization.
“Incorporate” means to publish or republish a Document, in whole or in part, as part of another Document.
An MMC is “eligible for relicensing” if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008.
The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing.
To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:
Copyright (C) year your name. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''.
If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “with...Texts.” line with this:
with the Invariant Sections being list their titles, with the Front-Cover Texts being list, and with the Back-Cover Texts being list.
If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.
If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.
*
: Fundamental Structure+
: Fundamental Structure--after-context
: Context Line Control--basic-regexp
: grep Programs--before-context
: Context Line Control--binary
: Other Options--binary-files
: File and Directory Selection--byte-offset
: Output Line Prefix Control--color
: General Output Control--colour
: General Output Control--context
: Context Line Control--count
: General Output Control--dereference-recursive
: File and Directory Selection--devices
: File and Directory Selection--directories
: File and Directory Selection--exclude
: File and Directory Selection--exclude-dir
: File and Directory Selection--exclude-from
: File and Directory Selection--extended-regexp
: grep Programs--file
: Matching Control--files-with-matches
: General Output Control--files-without-match
: General Output Control--fixed-strings
: grep Programs--group-separator
: Context Line Control--help
: Generic Program Information--ignore-case
: Matching Control--include
: File and Directory Selection--initial-tab
: Output Line Prefix Control--invert-match
: Matching Control--label
: Output Line Prefix Control--line-buffered
: Other Options--line-number
: Output Line Prefix Control--line-regexp
: Matching Control--max-count
: General Output Control--no-filename
: Output Line Prefix Control--no-messages
: General Output Control--null
: Output Line Prefix Control--null-data
: Other Options--only-matching
: General Output Control--perl-regexp
: grep Programs--quiet
: General Output Control--recursive
: File and Directory Selection--regexp=
pattern: Matching Control--silent
: General Output Control--text
: File and Directory Selection--unix-byte-offsets
: Output Line Prefix Control--version
: Generic Program Information--with-filename
: Output Line Prefix Control--word-regexp
: Matching Control-a
: File and Directory Selection-A
: Context Line Control-B
: Context Line Control-b
: Output Line Prefix Control-C
: Context Line Control-c
: General Output Control-d
: File and Directory Selection-D
: File and Directory Selection-E
: grep Programs-e
: Matching Control-F
: grep Programs-f
: Matching Control-G
: grep Programs-h
: Output Line Prefix Control-H
: Output Line Prefix Control-i
: Matching Control-l
: General Output Control-L
: General Output Control-m
: General Output Control-n
: Output Line Prefix Control-
num: Context Line Control-o
: General Output Control-P
: grep Programs-q
: General Output Control-R
: File and Directory Selection-r
: File and Directory Selection-s
: General Output Control-T
: Output Line Prefix Control-U
: Other Options-u
: Output Line Prefix Control-v
: Matching Control-V
: Generic Program Information-w
: Matching Control-x
: Matching Control-y
: Matching Control-z
: Other Options-Z
: Output Line Prefix Control.
: Fundamental Structure?
: Fundamental Structure_
N_GNU_nonoption_argv_flags_
environment variable: Environment Variablesalnum
character class: Character Classes and Bracket Expressionsalpha
character class: Character Classes and Bracket Expressionsblank
character class: Character Classes and Bracket Expressionsbn GREP_COLORS
capability: Environment Variablescntrl
character class: Character Classes and Bracket Expressionscx GREP_COLORS
capability: Environment Variablesdigit
character class: Character Classes and Bracket Expressionsfn GREP_COLORS
capability: Environment Variablesgraph
character class: Character Classes and Bracket ExpressionsGREP_COLOR
environment variable: Environment VariablesGREP_COLORS
environment variable: Environment VariablesGREP_OPTIONS
environment variable: Environment VariablesLANG
environment variable: Environment VariablesLANGUAGE
environment variable: Environment VariablesLC_ALL
environment variable: Environment VariablesLC_COLLATE
environment variable: Environment VariablesLC_CTYPE
environment variable: Environment VariablesLC_MESSAGES
environment variable: Environment Variablesln GREP_COLORS
capability: Environment Variableslower
character class: Character Classes and Bracket Expressionsmc GREP_COLORS
capability: Environment Variablesms GREP_COLORS
capability: Environment Variablesmt GREP_COLORS
capability: Environment Variablesne GREP_COLORS
capability: Environment VariablesPOSIXLY_CORRECT
environment variable: Environment Variablesprint
character class: Character Classes and Bracket Expressionspunct
character class: Character Classes and Bracket Expressionsrv GREP_COLORS
capability: Environment Variablessl GREP_COLORS
capability: Environment Variablesspace
character class: Character Classes and Bracket Expressionsupper
character class: Character Classes and Bracket Expressionsxdigit
character class: Character Classes and Bracket Expressions{,
m}
: Fundamental Structure{
n,
m}
: Fundamental Structure{
n,}
: Fundamental Structure{
n}
: Fundamental Structure