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grep branch, master, updated. v2.10-17-g1ca631f
|
From: |
Jim Meyering |
|
Subject: |
grep branch, master, updated. v2.10-17-g1ca631f |
|
Date: |
Mon, 12 Dec 2011 16:55:05 +0000 |
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "grep".
The branch, master has been updated
via 1ca631f8e3cffa22554865ac11903b5afa647c00 (commit)
from 0ba89c07c583fb7bc24225f6dca66fd066169497 (commit)
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not appeared on any other notification email; so we list those
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- Log -----------------------------------------------------------------
http://git.savannah.gnu.org/cgit/grep.git/commit/?id=1ca631f8e3cffa22554865ac11903b5afa647c00
commit 1ca631f8e3cffa22554865ac11903b5afa647c00
Author: Arnold D. Robbins <address@hidden>
Date: Thu Dec 8 20:31:44 2011 +0200
doc: improve grep.texi
* doc/grep.texi: General editing for improved aesthetics.
Also fix a few problems.
diff --git a/doc/grep.texi b/doc/grep.texi
index b1b879a..8b55d9a 100644
--- a/doc/grep.texi
+++ b/doc/grep.texi
@@ -72,7 +72,7 @@ This manual is for version @value{VERSION} of GNU Grep.
@cindex searching for a pattern
address@hidden searches the input files
address@hidden 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),
@@ -116,13 +116,13 @@ There can be zero or more @var{input_file_names}.
@section Command-line Options
@command{grep} comes with a rich set of options:
-some from @sc{posix.2} and some being @sc{gnu} extensions.
-Long option names are always a @sc{gnu} extension,
-even for options that are from @sc{posix} specifications.
-Options that are specified by @sc{posix},
+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 @sc{posix}-portable programming.
+to facilitate POSIX-portable programming.
A few option names are provided
for compatibility with older or more exotic implementations.
@@ -143,7 +143,7 @@ which variant of the @command{grep} matching engine is used.
@node Generic Program Information
@subsection Generic Program Information
address@hidden @samp
address@hidden @option
@item --help
@opindex --help
@@ -164,7 +164,7 @@ This version number should be included in all bug reports.
@node Matching Control
@subsection Matching Control
address@hidden @samp
address@hidden @option
@item -e @var{pattern}
@itemx address@hidden
@@ -174,7 +174,7 @@ This version number should be included in all bug reports.
Use @var{pattern} as the pattern.
This can be used to specify multiple search patterns,
or to protect a pattern beginning with a @samp{-}.
-(@samp{-e} is specified by @sc{posix}.)
+(@option{-e} is specified by POSIX.)
@item -f @var{file}
@itemx address@hidden
@@ -183,7 +183,7 @@ or to protect a pattern beginning with a @samp{-}.
@cindex pattern from file
Obtain patterns from @var{file}, one per line.
The empty file contains zero patterns, and therefore matches nothing.
-(@samp{-f} is specified by @sc{posix}.)
+(@option{-f} is specified by POSIX.)
@item -i
@itemx -y
@@ -193,8 +193,8 @@ The empty file contains zero patterns, and therefore
matches nothing.
@opindex --ignore-case
@cindex case insensitive search
Ignore case distinctions in both the pattern and the input files.
address@hidden is an obsolete synonym that is provided for compatibility.
-(@samp{-i} is specified by @sc{posix}.)
address@hidden is an obsolete synonym that is provided for compatibility.
+(@option{-i} is specified by POSIX.)
@item -v
@itemx --invert-match
@@ -203,7 +203,7 @@ Ignore case distinctions in both the pattern and the input
files.
@cindex invert matching
@cindex print non-matching lines
Invert the sense of matching, to select non-matching lines.
-(@samp{-v} is specified by @sc{posix}.)
+(@option{-v} is specified by POSIX.)
@item -w
@itemx --word-regexp
@@ -225,14 +225,14 @@ Word-constituent characters are letters, digits, and the
underscore.
@opindex --line-regexp
@cindex match the whole line
Select only those matches that exactly match the whole line.
-(@samp{-x} is specified by @sc{posix}.)
+(@option{-x} is specified by POSIX.)
@end table
@node General Output Control
@subsection General Output Control
address@hidden @samp
address@hidden @option
@item -c
@itemx --count
@@ -241,9 +241,9 @@ Select only those matches that exactly match the whole line.
@cindex counting lines
Suppress normal output;
instead print a count of matching lines for each input file.
-With the @samp{-v}, @samp{--invert-match} option,
+With the @option{-v} (@option{--invert-match}) option,
count non-matching lines.
-(@samp{-c} is specified by @sc{posix}.)
+(@option{-c} is specified by POSIX.)
@item address@hidden
@itemx address@hidden
@@ -254,11 +254,11 @@ Surround the matched (non-empty) strings, matching lines,
context lines,
file names, line numbers, byte offsets, and separators (for fields and
groups of context lines) with escape sequences to display them in color
on the terminal.
-The colors are defined by the environment variable @var{GREP_COLORS}
+The colors are defined by the environment variable @env{GREP_COLORS}
and default to @samp{ms=01;31:mc=01;31:sl=:cx=:fn=35:ln=32:bn=32:se=36}
for bold red matched text, magenta file names, green line numbers,
green byte offsets, cyan separators, and default terminal colors otherwise.
-The deprecated environment variable @var{GREP_COLOR} is still supported,
+The deprecated environment variable @env{GREP_COLOR} is still supported,
but its setting does not have priority;
it defaults to `01;31' (bold red)
which only covers the color for matched text.
@@ -272,7 +272,7 @@ which only covers the color for matched text.
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.
+The scanning of each file stops on the first match.
@item -l
@itemx --files-with-matches
@@ -282,8 +282,8 @@ The scanning of every file will stop on the first match.
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.
-(@samp{-l} is specified by @sc{posix}.)
+The scanning of each file stops on the first match.
+(@option{-l} is specified by POSIX.)
@item -m @var{num}
@itemx address@hidden
@@ -322,9 +322,9 @@ When @command{grep} stops after @var{num} matching lines,
it outputs any trailing context lines.
Since context does not include matching lines,
@command{grep} will stop when it encounters another matching line.
-When the @samp{-c} or @samp{--count} option is also used,
+When the @option{-c} or @option{--count} option is also used,
@command{grep} does not output a count greater than @var{num}.
-When the @samp{-v} or @samp{--invert-match} option is also used,
+When the @option{-v} or @option{--invert-match} option is also used,
@command{grep} stops after outputting @var{num} non-matching lines.
@item -o
@@ -345,8 +345,8 @@ with each such part on a separate output line.
Quiet; do not write anything to standard output.
Exit immediately with zero status if any match is found,
even if an error was detected.
-Also see the @samp{-s} or @samp{--no-messages} option.
-(@samp{-q} is specified by @sc{posix}.)
+Also see the @option{-s} or @option{--no-messages} option.
+(@option{-q} is specified by POSIX.)
@item -s
@itemx --no-messages
@@ -355,17 +355,18 @@ Also see the @samp{-s} or @samp{--no-messages} option.
@cindex suppress error messages
Suppress error messages about nonexistent or unreadable files.
Portability note:
-unlike @sc{gnu} @command{grep},
-7th Edition Unix @command{grep} did not conform to @sc{posix},
-because it lacked @samp{-q}
-and its @samp{-s} option behaved like
address@hidden @command{grep}'s @samp{-q} option.
address@hidden @command{grep} also lacked @samp{-q}
-but its @samp{-s} option behaved like @sc{gnu} @command{grep}'s.
+unlike GNU @command{grep},
+7th Edition Unix @command{grep} did not conform to POSIX,
+because it lacked @option{-q}
+and its @option{-s} option behaved like
+GNU @command{grep}'s @option{-q} address@hidden course, 7th Edition
+Unix predated POSIX by several years!}
+USG-style @command{grep} also lacked @option{-q}
+but its @option{-s} option behaved like GNU @command{grep}'s.
Portable shell scripts should avoid both
address@hidden and @samp{-s} and should redirect
address@hidden and @option{-s} and should redirect
standard and error output to @file{/dev/null} instead.
-(@samp{-s} is specified by @sc{posix}.)
+(@option{-s} is specified by POSIX.)
@end table
@@ -376,7 +377,7 @@ 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.
address@hidden @samp
address@hidden @option
@item -b
@itemx --byte-offset
@@ -385,11 +386,11 @@ regardless of the order in which these options were
specified.
@cindex byte offset
Print the 0-based byte offset within the input file
before each line of output.
-If @samp{-o} (@samp{--only-matching}) is specified,
+If @option{-o} (@option{--only-matching}) is specified,
print the offset of the matching part itself.
-When @command{grep} runs on @sc{ms-dos} or @sc{ms}-Windows,
+When @command{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;
+the @option{-u} (@option{--unix-byte-offsets}) option is used;
see below.
@item -H
@@ -427,7 +428,7 @@ gzip -cd foo.gz | grep --label=foo -H something
@opindex --line-number
@cindex line numbering
Prefix each line of output with the 1-based line number within its input file.
-(@samp{-n} is specified by @sc{posix}.)
+(@option{-n} is specified by POSIX.)
@item -T
@itemx --initial-tab
@@ -437,7 +438,7 @@ Prefix each line of output with the 1-based line number
within its input file.
Make sure that the first character of actual line content lies on a tab stop,
so that the alignment of tabs looks normal.
This is useful with options that prefix their output to the actual content:
address@hidden, @samp{-n}, and @samp{-b}.
address@hidden, @option{-n}, and @option{-b}.
In order to improve the probability that lines
from a single file will all start at the same column,
this also causes the line number and byte offset (if present)
@@ -447,23 +448,23 @@ to be printed in a minimum-size field width.
@itemx --unix-byte-offsets
@opindex -u
@opindex --unix-byte-offsets
address@hidden @sc{ms-dos}/@sc{ms}-Windows byte offsets
address@hidden byte offsets, on @sc{ms-dos}/@sc{ms}-Windows
address@hidden MS-DOS/MS-Windows byte offsets
address@hidden byte offsets, on MS-DOS/MS-Windows
Report Unix-style byte offsets.
This option causes @command{grep} to report byte offsets
as if the file were a Unix-style text file,
i.e., the byte offsets ignore the @code{CR} characters that were stripped.
This will produce results identical
to running @command{grep} on a Unix machine.
-This option has no effect unless the @samp{-b} option is also used;
-it has no effect on platforms other than @sc{ms-dos} and @sc{ms}-Windows.
+This option has no effect unless the @option{-b} option is also used;
+it has no effect on platforms other than MS-DOS and MS-Windows.
@item -Z
@itemx --null
@opindex -Z
@opindex --null
@cindex zero-terminated file names
-Output a zero byte (the @sc{ascii} @code{NUL} character)
+Output a zero byte (the ASCII @code{NUL} character)
instead of the character that normally follows a file name.
For example,
@samp{grep -lZ} outputs a zero byte after each file name
@@ -482,10 +483,10 @@ even those that contain newline characters.
Regardless of how these options are set,
@command{grep} will never print any given line more than once.
-If the @samp{-o} or @samp{--only-matching} option is specified,
+If the @option{-o} (@option{--only-matching}) option is specified,
these options have no effect and a warning is given upon their use.
address@hidden @samp
address@hidden @option
@item -A @var{num}
@itemx address@hidden
@@ -516,7 +517,7 @@ Print @var{num} lines of leading and trailing output
context.
@opindex --group-separator
@cindex group separator
When @option{-A}, @option{-B} or @option{-C} are in use,
-print @var{string} instead of @samp{--} around disjoint groups
+print @var{string} instead of @option{--} around disjoint groups
of lines.
@item --no-group-separator
@@ -527,26 +528,44 @@ print disjoint groups of lines adjacent to each other.
@end table
+Here are some points about how @command{grep} chooses
+the separator to print between prefix fields and line content:
+
address@hidden @bullet
address@hidden
Matching lines normally use @samp{:} as a separator
between prefix fields and actual line content.
+
address@hidden
Context (i.e., non-matching) lines use @samp{-} instead.
+
address@hidden
When no context is specified,
matching lines are simply output one right after another.
+
address@hidden
When nonzero context is specified,
lines that are adjacent in the input form a group
and are output one right after another, while
a separator appears by default between disjoint groups on a line
-of its own and without any prefix. The default separator
+of its own and without any prefix.
+
address@hidden
+The default separator
is @samp{--}, however whether to include it and its appearance
-can be changed with the options above. Each group may contain
+can be changed with the options above.
+
address@hidden
+Each group may contain
several matching lines when they are close enough to each other
that two otherwise adjacent but divided groups connect
and can just merge into a single contiguous one.
address@hidden itemize
@node File and Directory Selection
@subsection File and Directory Selection
address@hidden @samp
address@hidden @option
@item -a
@itemx --text
@@ -557,7 +576,7 @@ and can just merge into a single contiguous one.
Process a binary file as if it were text;
this is equivalent to the @samp{--binary-files=text} option.
address@hidden address@hidden
address@hidden address@hidden
@opindex --binary-files
@cindex binary files
If the first few bytes of a file indicate that the file contains binary data,
@@ -566,12 +585,15 @@ By default, @var{type} is @samp{binary},
and @command{grep} normally outputs either
a one-line message saying that a binary file matches,
or no message if there is no match.
+
If @var{type} is @samp{without-match},
@command{grep} assumes that a binary file does not match;
-this is equivalent to the @samp{-I} option.
+this is equivalent to the @option{-I} option.
+
If @var{type} is @samp{text},
@command{grep} processes a binary file as if it were text;
-this is equivalent to the @samp{-a} option.
+this is equivalent to the @option{-a} option.
+
@emph{Warning:} @samp{--binary-files=text} might output binary garbage,
which can have nasty side effects
if the output is a terminal and
@@ -602,7 +624,7 @@ to print error messages for every directory or silently
skip them).
If @var{action} is @samp{skip}, directories are silently skipped.
If @var{action} is @samp{recurse},
@command{grep} reads all files under each directory, recursively;
-this is equivalent to the @samp{-r} option.
+this is equivalent to the @option{-r} option.
@item address@hidden
@opindex --exclude
@@ -620,7 +642,7 @@ and @code{\} to quote a wildcard or backslash character
literally.
@cindex searching directory trees
Skip files whose base name matches any of the file-name globs
read from @var{file} (using wildcard matching as described
-under @samp{--exclude}).
+under @option{--exclude}).
@item address@hidden
@opindex --exclude-dir
@@ -637,7 +659,7 @@ this is equivalent to the
@samp{--binary-files=without-match} option.
@cindex include files
@cindex searching directory trees
Search only files whose base name matches @var{glob}
-(using wildcard matching as described under @samp{--exclude}).
+(using wildcard matching as described under @option{--exclude}).
@item -r
@itemx -R
@@ -655,7 +677,7 @@ This is the same as the @samp{--directories=recurse} option.
@node Other Options
@subsection Other Options
address@hidden @samp
address@hidden @option
@item --line-buffered
@opindex --line-buffered
@@ -675,21 +697,21 @@ better performance.
@itemx --binary
@opindex -U
@opindex --binary
address@hidden @sc{ms-dos}/@sc{ms}-Windows binary files
address@hidden binary files, @sc{ms-dos}/@sc{ms}-Windows
address@hidden MS-DOS/MS-Windows binary files
address@hidden binary files, MS-DOS/MS-Windows
Treat the file(s) as binary.
-By default, under @sc{ms-dos} and @sc{ms}-Windows,
+By default, under MS-DOS and MS-Windows,
@command{grep} guesses the file type
by looking at the contents of the first 32kB read from the file.
If @command{grep} decides the file is a text file,
it strips the @code{CR} characters from the original file contents
(to make regular expressions with @code{^} and @code{$} work correctly).
-Specifying @samp{-U} overrules this guesswork,
+Specifying @option{-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 @code{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 @sc{ms-dos} and @sc{ms}-Windows.
+on platforms other than MS-DOS and MS-Windows.
@item -z
@itemx --null-data
@@ -697,8 +719,8 @@ on platforms other than @sc{ms-dos} and @sc{ms}-Windows.
@opindex --null-data
@cindex zero-terminated lines
Treat the input as a set of lines, each terminated by a zero byte (the
address@hidden @code{NUL} character) instead of a newline.
-Like the @samp{-Z} or @samp{--null} option,
+ASCII @code{NUL} character) instead of a newline.
+Like the @option{-Z} or @option{--null} option,
this option can be used with commands like
@samp{sort -z} to process arbitrary file names.
@@ -722,7 +744,41 @@ for the @code{LC_MESSAGES} category.
The @samp{C} locale is used if none of these environment variables are set,
if the locale catalog is not installed,
or if @command{grep} was not compiled
-with national language support (@sc{nls}).
+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.
address@hidden takes care of assembling the result
+into a complete SGR sequence (@address@hidden).
+Common values to concatenate include
address@hidden for bold,
address@hidden for underline,
address@hidden for blink,
address@hidden for inverse,
address@hidden for default foreground color,
address@hidden to @samp{37} for foreground colors,
address@hidden to @samp{97} for 16-color mode foreground colors,
address@hidden;5;0} to @samp{38;5;255}
+for 88-color and 256-color modes foreground colors,
address@hidden for default background color,
address@hidden to @samp{47} for background colors,
address@hidden to @samp{107} for 16-color mode background colors,
+and @samp{48;5;0} to @samp{48;5;255}
+for 88-color and 256-color modes background colors.
+
+The two-letter names used in the @env{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 @code{terminfo} library.
@cindex environment variables
@@ -747,13 +803,13 @@ specify an option containing whitespace or a backslash.
@vindex GREP_COLOR @r{environment variable}
@cindex highlight markers
This variable specifies the color used to highlight matched (non-empty) text.
-It is deprecated in favor of @code{GREP_COLORS}, but still supported.
-The @samp{mt}, @samp{ms}, and @samp{mc} capabilities of @code{GREP_COLORS}
+It is deprecated in favor of @env{GREP_COLORS}, but still supported.
+The @samp{mt}, @samp{ms}, and @samp{mc} capabilities of @env{GREP_COLORS}
have priority over it.
It can only specify the color used to highlight
the matching non-empty text in any matching line
-(a selected line when the @samp{-v} command-line option is omitted,
-or a context line when @samp{-v} is specified).
+(a selected line when the @option{-v} command-line option is omitted,
+or a context line when @option{-v} is specified).
The default is @samp{01;31},
which means a bold red foreground text on the terminal's default background.
@@ -762,7 +818,7 @@ which means a bold red foreground text on the terminal's
default background.
@cindex highlight markers
This variable specifies the colors and other attributes
used to highlight various parts of the output.
-Its value is a colon-separated list of capabilities
+Its value is a colon-separated list of @code{terminfo} capabilities
that defaults to @samp{ms=01;31:mc=01;31:sl=:cx=:fn=35:ln=32:bn=32:se=36}
with the @samp{rv} and @samp{ne} boolean capabilities omitted (i.e., false).
Supported capabilities are as follows.
@@ -772,10 +828,10 @@ Supported capabilities are as follows.
@vindex sl GREP_COLORS @r{capability}
SGR substring for whole selected lines
(i.e.,
-matching lines when the @samp{-v} command-line option is omitted,
-or non-matching lines when @samp{-v} is specified).
+matching lines when the @option{-v} command-line option is omitted,
+or non-matching lines when @option{-v} is specified).
If however the boolean @samp{rv} capability
-and the @samp{-v} command-line option are both specified,
+and the @option{-v} command-line option are both specified,
it applies to context matching lines instead.
The default is empty (i.e., the terminal's default color pair).
@@ -783,10 +839,10 @@ The default is empty (i.e., the terminal's default color
pair).
@vindex cx GREP_COLORS @r{capability}
SGR substring for whole context lines
(i.e.,
-non-matching lines when the @samp{-v} command-line option is omitted,
-or matching lines when @samp{-v} is specified).
+non-matching lines when the @option{-v} command-line option is omitted,
+or matching lines when @option{-v} is specified).
If however the boolean @samp{rv} capability
-and the @samp{-v} command-line option are both specified,
+and the @option{-v} command-line option are both specified,
it applies to selected non-matching lines instead.
The default is empty (i.e., the terminal's default color pair).
@@ -794,15 +850,15 @@ The default is empty (i.e., the terminal's default color
pair).
@vindex rv GREP_COLORS @r{capability}
Boolean value that reverses (swaps) the meanings of
the @samp{sl=} and @samp{cx=} capabilities
-when the @samp{-v} command-line option is specified.
+when the @option{-v} command-line option is specified.
The default is false (i.e., the capability is omitted).
@item mt=01;31
@vindex mt GREP_COLORS @r{capability}
SGR substring for matching non-empty text in any matching line
(i.e.,
-a selected line when the @samp{-v} command-line option is omitted,
-or a context line when @samp{-v} is specified).
+a selected line when the @option{-v} command-line option is omitted,
+or a context line when @option{-v} is specified).
Setting this is equivalent to setting both @samp{ms=} and @samp{mc=}
at once to the same value.
The default is a bold red text foreground over the current line background.
@@ -810,17 +866,17 @@ The default is a bold red text foreground over the
current line background.
@item ms=01;31
@vindex ms GREP_COLORS @r{capability}
SGR substring for matching non-empty text in a selected line.
-(This is only used when the @samp{-v} command-line option is omitted.)
+(This is used only when the @option{-v} command-line option is omitted.)
The effect of the @samp{sl=} (or @samp{cx=} if @samp{rv}) capability
-remains active when this kicks in.
+remains active when this takes effect.
The default is a bold red text foreground over the current line background.
@item mc=01;31
@vindex mc GREP_COLORS @r{capability}
SGR substring for matching non-empty text in a context line.
-(This is only used when the @samp{-v} command-line option is specified.)
+(This is used only when the @option{-v} command-line option is specified.)
The effect of the @samp{cx=} (or @samp{sl=} if @samp{rv}) capability
-remains active when this kicks in.
+remains active when this takes effect.
The default is a bold red text foreground over the current line background.
@item fn=35
@@ -855,7 +911,7 @@ each time a colorized item ends.
This is needed on terminals on which EL is not supported.
It is otherwise useful on terminals
for which the @code{back_color_erase}
-(@code{bce}) boolean terminfo capability does not apply,
+(@code{bce}) boolean @code{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).
@@ -864,28 +920,6 @@ The default is false (i.e., the capability is omitted).
Note that boolean capabilities have no @samp{=}... part.
They are omitted (i.e., false) by default and become true when specified.
-See the Select Graphic Rendition (SGR) section
-in the documentation of your text terminal
-for permitted values and their meaning as character attributes.
-These substring values are integers in decimal representation
-and can be concatenated with semicolons.
address@hidden takes care of assembling the result
-into a complete SGR sequence (@address@hidden).
-Common values to concatenate include
address@hidden for bold,
address@hidden for underline,
address@hidden for blink,
address@hidden for inverse,
address@hidden for default foreground color,
address@hidden to @samp{37} for foreground colors,
address@hidden to @samp{97} for 16-color mode foreground colors,
address@hidden;5;0} to @samp{38;5;255}
-for 88-color and 256-color modes foreground colors,
address@hidden for default background color,
address@hidden to @samp{47} for background colors,
address@hidden to @samp{107} for 16-color mode background colors,
-and @samp{48;5;0} to @samp{48;5;255}
-for 88-color and 256-color modes background colors.
@item LC_ALL
@itemx LC_COLLATE
@@ -926,9 +960,9 @@ The default @samp{C} locale uses American English messages.
@item POSIXLY_CORRECT
@vindex POSIXLY_CORRECT @r{environment variable}
-If set, @command{grep} behaves as @sc{posix.2} requires; otherwise,
address@hidden behaves more like other @sc{gnu} programs.
address@hidden
+If set, @command{grep} behaves as POSIX requires; otherwise,
address@hidden behaves more like other GNU programs.
+POSIX
requires that options that
follow file names must be treated as file names;
by default,
@@ -946,7 +980,7 @@ even if it appears to be one.
A shell can put this variable in the environment for each command it runs,
specifying which operands are the results of file name wildcard expansion
and therefore should not be treated as options.
-This behavior is available only with the @sc{gnu} C library,
+This behavior is available only with the GNU C library,
and only when @code{POSIXLY_CORRECT} is not set.
@end table
@@ -961,7 +995,7 @@ Normally, the exit status is 0 if selected lines are found
and 1 otherwise.
But the exit status is 2 if an error occurred, unless the @option{-q} or
@option{--quiet} or @option{--silent} option is used and a selected line
is found.
-Note, however, that @sc{posix} only mandates,
+Note, however, that POSIX only mandates,
for programs such as @command{grep}, @command{cmp}, and @command{diff},
that the exit status in case of error be greater than 1;
it is therefore advisable, for the sake of portability,
@@ -982,7 +1016,7 @@ By default, @command{grep} prints the matching lines.
There are four major variants of @command{grep},
controlled by the following options.
address@hidden @samp
address@hidden @option
@item -G
@itemx --basic-regexp
@@ -998,7 +1032,7 @@ This is the default.
@opindex --extended-regexp
@cindex matching extended regular expressions
Interpret the pattern as an extended regular expression (ERE).
-(@samp{-E} is specified by @sc{posix}.)
+(@option{-E} is specified by POSIX.)
@item -F
@itemx --fixed-strings
@@ -1007,7 +1041,7 @@ Interpret the pattern as an extended regular expression
(ERE).
@cindex matching fixed strings
Interpret the pattern as a list of fixed strings, separated
by newlines, any of which is to be matched.
-(@samp{-F} is specified by @sc{posix}.)
+(@option{-F} is specified by POSIX.)
@item -P
@itemx --perl-regexp
@@ -1040,15 +1074,15 @@ by using various operators to combine smaller
expressions.
@command{grep} understands
three different versions of regular expression syntax:
``basic,'' (BRE) ``extended'' (ERE) and ``perl''.
-In @sc{gnu} @command{grep},
-there is no difference in available functionality between basic and
+In GNU @command{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 pcresyntax(3) and pcrepattern(3), but may not be
-available on every system.
+documented in the @i{pcresyntax}(3) and @i{pcrepattern}(3) manual pages,
+but may not be available on every system.
@menu
* Fundamental Structure::
@@ -1171,7 +1205,7 @@ of bracket expressions, you can use the @samp{C} locale
by setting the
Finally, certain named classes of characters are predefined within
bracket expressions, as follows.
Their interpretation depends on the @code{LC_CTYPE} locale;
-for example, [[:alnum:]] means the character class of numbers and letters
+for example, @samp{[[:alnum:]]} means the character class of numbers and
letters
in the current locale.
@cindex classes of characters
@@ -1182,13 +1216,13 @@ in the current locale.
@opindex alnum @r{character class}
@cindex alphanumeric characters
Alphanumeric characters:
address@hidden:alpha:]} and @samp{[:digit:]}; in the @samp{C} locale and
@sc{ascii} character encoding, this is the same as @samp{[0-9A-Za-z]}.
address@hidden:alpha:]} and @samp{[:digit:]}; in the @samp{C} locale and ASCII
character encoding, this is the same as @samp{[0-9A-Za-z]}.
@item [:alpha:]
@opindex alpha @r{character class}
@cindex alphabetic characters
Alphabetic characters:
address@hidden:lower:]} and @samp{[:upper:]}; in the @samp{C} locale and
@sc{ascii} character encoding, this is the same as @samp{[A-Za-z]}.
address@hidden:lower:]} and @samp{[:upper:]}; in the @samp{C} locale and ASCII
character encoding, this is the same as @samp{[A-Za-z]}.
@item [:blank:]
@opindex blank @r{character class}
@@ -1200,7 +1234,7 @@ space and tab.
@opindex cntrl @r{character class}
@cindex control characters
Control characters.
-In @sc{ascii}, these characters have octal codes 000
+In ASCII, these characters have octal codes 000
through 037, and 177 (@code{DEL}).
In other character sets, these are
the equivalent characters, if any.
@@ -1220,7 +1254,7 @@ Graphical characters:
@item [:lower:]
@opindex lower @r{character class}
@cindex lower-case letters
-Lower-case letters; in the @samp{C} locale and @sc{ascii} character
+Lower-case letters; in the @samp{C} locale and ASCII character
encoding, this is
@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}.
@@ -1233,7 +1267,7 @@ Printable characters:
@item [:punct:]
@opindex punct @r{character class}
@cindex punctuation characters
-Punctuation characters; in the @samp{C} locale and @sc{ascii} character
+Punctuation characters; in the @samp{C} locale and ASCII character
encoding, this is
@code{!@: " # $ % & ' ( ) * + , - .@: / : ; < = > ?@: @@ [ \ ] ^ _ ` @{ | @}
~}.
@@ -1248,7 +1282,7 @@ tab, newline, vertical tab, form feed, carriage return,
and space.
@item [:upper:]
@opindex upper @r{character class}
@cindex upper-case letters
-Upper-case letters: in the @samp{C} locale and @sc{ascii} character
+Upper-case letters: in the @samp{C} locale and ASCII character
encoding, this is
@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}.
@@ -1318,28 +1352,28 @@ takes a special meaning:
@table @samp
address@hidden @samp{\b}
address@hidden \b
Match the empty string at the edge of a word.
address@hidden @samp{\B}
address@hidden \B
Match the empty string provided it's not at the edge of a word.
address@hidden @samp{\<}
address@hidden \<
Match the empty string at the beginning of word.
address@hidden @samp{\>}
address@hidden \>
Match the empty string at the end of word.
address@hidden @samp{\w}
-Match word constituent, it is a synonym for @samp{[[:alnum:]]}.
address@hidden \w
+Match word constituent, it is a synonym for @samp{[[:alnum:]_]}.
address@hidden @samp{\W}
-Match non-word constituent, it is a synonym for @samp{[^[:alnum:]]}.
address@hidden \W
+Match non-word constituent, it is a synonym for @samp{[^[:alnum:]_]}.
address@hidden @samp{\s}
address@hidden \s
Match whitespace, it is a synonym for @samp{[[:space:]]}.
address@hidden @samp{\S}
address@hidden \S
Match non-whitespace, it is a synonym for @samp{[^[:space:]]}.
@end table
@@ -1353,6 +1387,8 @@ For example, @samp{\brat\b} matches the separate word
@samp{rat},
The caret @samp{^} and the dollar sign @samp{$} are meta-characters that
respectively match the empty string at the beginning and end of a line.
+They are termed @dfn{anchors}, since they force the match to be ``anchored''
+to beginning or end of a line, respectively.
@node Back-references and Subexpressions
@section Back-references and Subexpressions
@@ -1368,7 +1404,7 @@ the back-reference makes the whole match fail.
For example, @samp{a(.)|b\1}
will not match @samp{ba}.
When multiple regular expressions are given with
address@hidden or from a file (@samp{-f file}),
address@hidden or from a file (@samp{-f @var{file}}),
back-references are local to each expression.
@node Basic vs Extended
@@ -1386,13 +1422,13 @@ and some @command{egrep} implementations support
@address@hidden instead, so
portable scripts should avoid @address@hidden in @samp{grep@ -E} patterns and
should use @address@hidden to match a literal @address@hidden
address@hidden @command{grep@ -E} attempts to support traditional usage by
+GNU @command{grep@ -E} attempts to support traditional usage by
assuming that @address@hidden is not special if it would be the start of an
invalid interval specification.
For example, the command
@samp{grep@ -E@ '@{1'} searches for the two-character string @address@hidden
instead of reporting a syntax error in the regular expression.
address@hidden allows this behavior as an extension, but portable scripts
+POSIX allows this behavior as an extension, but portable scripts
should avoid it.
@@ -1400,7 +1436,7 @@ should avoid it.
@chapter Usage
@cindex usage, examples
-Here is an example command that invokes @sc{gnu} @command{grep}:
+Here is an example command that invokes GNU @command{grep}:
@example
grep -i 'hello.*world' menu.h main.c
@@ -1411,7 +1447,7 @@ This lists all lines in the files @file{menu.h} and
@file{main.c} that
contain the string @samp{hello} followed by the string @samp{world};
this is because @samp{.*} matches zero or more characters within a line.
@xref{Regular Expressions}.
-The @samp{-i} option causes @command{grep}
+The @option{-i} option causes @command{grep}
to ignore case, causing it to match the line @samp{Hello, world!}, which
it would not otherwise match.
@xref{Invoking}, for more details about
@@ -1478,7 +1514,7 @@ grep -e '--cut here--' *
@noindent
searches for all lines matching @samp{--cut here--}.
-Without @samp{-e},
+Without @option{-e},
@command{grep} would attempt to parse @samp{--cut here--} as a list of
options.
@@ -1529,7 +1565,7 @@ gets you:
/etc/passwd:eli:x:2098:1000:Eli Smith:/home/eli:/bin/bash
@end example
-Alternatively, use @samp{-H}, which is a @sc{gnu} extension:
+Alternatively, use @option{-H}, which is a GNU extension:
@example
grep -H 'eli' /etc/passwd
@@ -1556,13 +1592,13 @@ Why does @command{grep} report ``Binary file matches''?
If @command{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 @sc{gnu} @command{grep} suppresses output from
+So GNU @command{grep} suppresses output from
files that appear to be binary files.
-To force @sc{gnu} @command{grep}
+To force GNU @command{grep}
to output lines even from files that appear to be binary, use the
address@hidden or @samp{--binary-files=text} option.
address@hidden or @samp{--binary-files=text} option.
To eliminate the
-``Binary file matches'' messages, use the @samp{-I} or
+``Binary file matches'' messages, use the @option{-I} or
@samp{--binary-files=without-match} option.
@item
@@ -1571,11 +1607,11 @@ Why doesn't @samp{grep -lv} print non-matching file
names?
@samp{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 @samp{-L} or @samp{--files-without-match}
+matching lines, use the @option{-L} or @option{--files-without-match}
option.
@item
-I can do @sc{or} with @samp{|}, but what about @sc{and}?
+I can do ``OR'' with @samp{|}, but what about ``AND''?
@example
grep 'paul' /etc/motd | grep 'franc,ois'
@@ -1605,7 +1641,7 @@ a palindrome of 4 characters can be written with a BRE:
grep -w -e '\(.\)\(.\).\2\1' file
@end example
-It matches the word "radar" or "civic".
+It matches the word ``radar'' or ``civic.''
Guglielmo Bondioni proposed a single RE
that finds all palindromes up to 19 characters long
@@ -1615,7 +1651,7 @@ using @w{9 subexpressions} and @w{9 back-references}:
grep -E -e '^(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?).?\9\8\7\6\5\4\3\2\1$' file
@end smallexample
-Note this is done by using @sc{gnu} ERE extensions;
+Note this is done by using GNU ERE extensions;
it might not be portable to other implementations of @command{grep}.
@item
@@ -1704,13 +1740,13 @@ Back-references are very slow, and may require
exponential time.
@chapter Copying
@cindex copying
-GNU grep is licensed under the GNU GPL, which makes it @dfn{free
+GNU @command{grep} is licensed under the GNU GPL, which makes it @dfn{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
+run and change @command{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.
-----------------------------------------------------------------------
Summary of changes:
doc/grep.texi | 344 +++++++++++++++++++++++++++++++-------------------------
1 files changed, 190 insertions(+), 154 deletions(-)
hooks/post-receive
--
grep
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