--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libraries/spcre/libpcre/pcre/doc/pcregrep.1	Wed Jun 23 15:52:26 2010 +0100
@@ -0,0 +1,463 @@
+.TH PCREGREP 1
+.SH NAME
+pcregrep - a grep with Perl-compatible regular expressions.
+.SH SYNOPSIS
+.B pcregrep [options] [long options] [pattern] [path1 path2 ...]
+.
+.SH DESCRIPTION
+.rs
+.sp
+\fBpcregrep\fP searches files for character patterns, in the same way as other
+grep commands do, but it uses the PCRE regular expression library to support
+patterns that are compatible with the regular expressions of Perl 5. See
+.\" HREF
+\fBpcrepattern\fP(3)
+.\"
+for a full description of syntax and semantics of the regular expressions
+that PCRE supports.
+.P
+Patterns, whether supplied on the command line or in a separate file, are given
+without delimiters. For example:
+.sp
+  pcregrep Thursday /etc/motd
+.sp
+If you attempt to use delimiters (for example, by surrounding a pattern with
+slashes, as is common in Perl scripts), they are interpreted as part of the
+pattern. Quotes can of course be used to delimit patterns on the command line
+because they are interpreted by the shell, and indeed they are required if a
+pattern contains white space or shell metacharacters.
+.P
+The first argument that follows any option settings is treated as the single
+pattern to be matched when neither \fB-e\fP nor \fB-f\fP is present.
+Conversely, when one or both of these options are used to specify patterns, all
+arguments are treated as path names. At least one of \fB-e\fP, \fB-f\fP, or an
+argument pattern must be provided.
+.P
+If no files are specified, \fBpcregrep\fP reads the standard input. The
+standard input can also be referenced by a name consisting of a single hyphen.
+For example:
+.sp
+  pcregrep some-pattern /file1 - /file3
+.sp
+By default, each line that matches a pattern is copied to the standard
+output, and if there is more than one file, the file name is output at the
+start of each line, followed by a colon. However, there are options that can
+change how \fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it
+possible to search for patterns that span line boundaries. What defines a line
+boundary is controlled by the \fB-N\fP (\fB--newline\fP) option.
+.P
+Patterns are limited to 8K or BUFSIZ characters, whichever is the greater.
+BUFSIZ is defined in \fB<stdio.h>\fP. When there is more than one pattern
+(specified by the use of \fB-e\fP and/or \fB-f\fP), each pattern is applied to
+each line in the order in which they are defined, except that all the \fB-e\fP
+patterns are tried before the \fB-f\fP patterns. As soon as one pattern matches
+(or fails to match when \fB-v\fP is used), no further patterns are considered.
+.P
+When \fB--only-matching\fP, \fB--file-offsets\fP, or \fB--line-offsets\fP
+is used, the output is the part of the line that matched (either shown
+literally, or as an offset). In this case, scanning resumes immediately
+following the match, so that further matches on the same line can be found.
+If there are multiple patterns, they are all tried on the remainder of the
+line. However, patterns that follow the one that matched are not tried on the
+earlier part of the line.
+.P
+If the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variable is set,
+\fBpcregrep\fP uses the value to set a locale when calling the PCRE library.
+The \fB--locale\fP option can be used to override this.
+.
+.SH "SUPPORT FOR COMPRESSED FILES"
+.rs
+.sp
+It is possible to compile \fBpcregrep\fP so that it uses \fBlibz\fP or
+\fBlibbz2\fP to read files whose names end in \fB.gz\fP or \fB.bz2\fP,
+respectively. You can find out whether your binary has support for one or both
+of these file types by running it with the \fB--help\fP option. If the
+appropriate support is not present, files are treated as plain text. The
+standard input is always so treated.
+.
+.SH OPTIONS
+.rs
+.TP 10
+\fB--\fP
+This terminate the list of options. It is useful if the next item on the
+command line starts with a hyphen but is not an option. This allows for the
+processing of patterns and filenames that start with hyphens.
+.TP
+\fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP
+Output \fInumber\fP lines of context after each matching line. If filenames
+and/or line numbers are being output, a hyphen separator is used instead of a
+colon for the context lines. A line containing "--" is output between each
+group of lines, unless they are in fact contiguous in the input file. The value
+of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
+guarantees to have up to 8K of following text available for context output.
+.TP
+\fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP
+Output \fInumber\fP lines of context before each matching line. If filenames
+and/or line numbers are being output, a hyphen separator is used instead of a
+colon for the context lines. A line containing "--" is output between each
+group of lines, unless they are in fact contiguous in the input file. The value
+of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
+guarantees to have up to 8K of preceding text available for context output.
+.TP
+\fB-C\fP \fInumber\fP, \fB--context=\fP\fInumber\fP
+Output \fInumber\fP lines of context both before and after each matching line.
+This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value.
+.TP
+\fB-c\fP, \fB--count\fP
+Do not output individual lines; instead just output a count of the number of
+lines that would otherwise have been output. If several files are given, a
+count is output for each of them. In this mode, the \fB-A\fP, \fB-B\fP, and
+\fB-C\fP options are ignored.
+.TP
+\fB--colour\fP, \fB--color\fP
+If this option is given without any data, it is equivalent to "--colour=auto".
+If data is required, it must be given in the same shell item, separated by an
+equals sign.
+.TP
+\fB--colour=\fP\fIvalue\fP, \fB--color=\fP\fIvalue\fP
+This option specifies under what circumstances the part of a line that matched
+a pattern should be coloured in the output. The value may be "never" (the
+default), "always", or "auto". In the latter case, colouring happens only if
+the standard output is connected to a terminal. The colour can be specified by
+setting the environment variable PCREGREP_COLOUR or PCREGREP_COLOR. The value
+of this variable should be a string of two numbers, separated by a semicolon.
+They are copied directly into the control string for setting colour on a
+terminal, so it is your responsibility to ensure that they make sense. If
+neither of the environment variables is set, the default is "1;31", which gives
+red.
+.TP
+\fB-D\fP \fIaction\fP, \fB--devices=\fP\fIaction\fP
+If an input path is not a regular file or a directory, "action" specifies how
+it is to be processed. Valid values are "read" (the default) or "skip"
+(silently skip the path).
+.TP
+\fB-d\fP \fIaction\fP, \fB--directories=\fP\fIaction\fP
+If an input path is a directory, "action" specifies how it is to be processed.
+Valid values are "read" (the default), "recurse" (equivalent to the \fB-r\fP
+option), or "skip" (silently skip the path). In the default case, directories
+are read as if they were ordinary files. In some operating systems the effect
+of reading a directory like this is an immediate end-of-file.
+.TP
+\fB-e\fP \fIpattern\fP, \fB--regex=\fP\fIpattern\fP, \fB--regexp=\fP\fIpattern\fP
+Specify a pattern to be matched. This option can be used multiple times in
+order to specify several patterns. It can also be used as a way of specifying a
+single pattern that starts with a hyphen. When \fB-e\fP is used, no argument
+pattern is taken from the command line; all arguments are treated as file
+names. There is an overall maximum of 100 patterns. They are applied to each
+line in the order in which they are defined until one matches (or fails to
+match if \fB-v\fP is used). If \fB-f\fP is used with \fB-e\fP, the command line
+patterns are matched first, followed by the patterns from the file, independent
+of the order in which these options are specified. Note that multiple use of
+\fB-e\fP is not the same as a single pattern with alternatives. For example,
+X|Y finds the first character in a line that is X or Y, whereas if the two
+patterns are given separately, \fBpcregrep\fP finds X if it is present, even if
+it follows Y in the line. It finds Y only if there is no X in the line. This
+really matters only if you are using \fB-o\fP to show the part(s) of the line
+that matched.
+.TP
+\fB--exclude\fP=\fIpattern\fP
+When \fBpcregrep\fP is searching the files in a directory as a consequence of
+the \fB-r\fP (recursive search) option, any regular files whose names match the
+pattern are excluded. Subdirectories are not excluded by this option; they are
+searched recursively, subject to the \fB--exclude_dir\fP and
+\fB--include_dir\fP options. The pattern is a PCRE regular expression, and is
+matched against the final component of the file name (not the entire path). If
+a file name matches both \fB--include\fP and \fB--exclude\fP, it is excluded.
+There is no short form for this option.
+.TP
+\fB--exclude_dir\fP=\fIpattern\fP
+When \fBpcregrep\fP is searching the contents of a directory as a consequence
+of the \fB-r\fP (recursive search) option, any subdirectories whose names match
+the pattern are excluded. (Note that the \fP--exclude\fP option does not affect
+subdirectories.) The pattern is a PCRE regular expression, and is matched
+against the final component of the name (not the entire path). If a
+subdirectory name matches both \fB--include_dir\fP and \fB--exclude_dir\fP, it
+is excluded. There is no short form for this option.
+.TP
+\fB-F\fP, \fB--fixed-strings\fP
+Interpret each pattern as a list of fixed strings, separated by newlines,
+instead of as a regular expression. The \fB-w\fP (match as a word) and \fB-x\fP
+(match whole line) options can be used with \fB-F\fP. They apply to each of the
+fixed strings. A line is selected if any of the fixed strings are found in it
+(subject to \fB-w\fP or \fB-x\fP, if present).
+.TP
+\fB-f\fP \fIfilename\fP, \fB--file=\fP\fIfilename\fP
+Read a number of patterns from the file, one per line, and match them against
+each line of input. A data line is output if any of the patterns match it. The
+filename can be given as "-" to refer to the standard input. When \fB-f\fP is
+used, patterns specified on the command line using \fB-e\fP may also be
+present; they are tested before the file's patterns. However, no other pattern
+is taken from the command line; all arguments are treated as file names. There
+is an overall maximum of 100 patterns. Trailing white space is removed from
+each line, and blank lines are ignored. An empty file contains no patterns and
+therefore matches nothing. See also the comments about multiple patterns versus
+a single pattern with alternatives in the description of \fB-e\fP above.
+.TP
+\fB--file-offsets\fP
+Instead of showing lines or parts of lines that match, show each match as an
+offset from the start of the file and a length, separated by a comma. In this
+mode, no context is shown. That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP
+options are ignored. If there is more than one match in a line, each of them is
+shown separately. This option is mutually exclusive with \fB--line-offsets\fP
+and \fB--only-matching\fP.
+.TP
+\fB-H\fP, \fB--with-filename\fP
+Force the inclusion of the filename at the start of output lines when searching
+a single file. By default, the filename is not shown in this case. For matching
+lines, the filename is followed by a colon and a space; for context lines, a
+hyphen separator is used. If a line number is also being output, it follows the
+file name without a space.
+.TP
+\fB-h\fP, \fB--no-filename\fP
+Suppress the output filenames when searching multiple files. By default,
+filenames are shown when multiple files are searched. For matching lines, the
+filename is followed by a colon and a space; for context lines, a hyphen
+separator is used. If a line number is also being output, it follows the file
+name without a space.
+.TP
+\fB--help\fP
+Output a help message, giving brief details of the command options and file
+type support, and then exit.
+.TP
+\fB-i\fP, \fB--ignore-case\fP
+Ignore upper/lower case distinctions during comparisons.
+.TP
+\fB--include\fP=\fIpattern\fP
+When \fBpcregrep\fP is searching the files in a directory as a consequence of
+the \fB-r\fP (recursive search) option, only those regular files whose names
+match the pattern are included. Subdirectories are always included and searched
+recursively, subject to the \fP--include_dir\fP and \fB--exclude_dir\fP
+options. The pattern is a PCRE regular expression, and is matched against the
+final component of the file name (not the entire path). If a file name matches
+both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no short
+form for this option.
+.TP
+\fB--include_dir\fP=\fIpattern\fP
+When \fBpcregrep\fP is searching the contents of a directory as a consequence
+of the \fB-r\fP (recursive search) option, only those subdirectories whose
+names match the pattern are included. (Note that the \fB--include\fP option
+does not affect subdirectories.) The pattern is a PCRE regular expression, and
+is matched against the final component of the name (not the entire path). If a
+subdirectory name matches both \fB--include_dir\fP and \fB--exclude_dir\fP, it
+is excluded. There is no short form for this option.
+.TP
+\fB-L\fP, \fB--files-without-match\fP
+Instead of outputting lines from the files, just output the names of the files
+that do not contain any lines that would have been output. Each file name is
+output once, on a separate line.
+.TP
+\fB-l\fP, \fB--files-with-matches\fP
+Instead of outputting lines from the files, just output the names of the files
+containing lines that would have been output. Each file name is output
+once, on a separate line. Searching stops as soon as a matching line is found
+in a file.
+.TP
+\fB--label\fP=\fIname\fP
+This option supplies a name to be used for the standard input when file names
+are being output. If not supplied, "(standard input)" is used. There is no
+short form for this option.
+.TP
+\fB--line-offsets\fP
+Instead of showing lines or parts of lines that match, show each match as a
+line number, the offset from the start of the line, and a length. The line
+number is terminated by a colon (as usual; see the \fB-n\fP option), and the
+offset and length are separated by a comma. In this mode, no context is shown.
+That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP options are ignored. If there is
+more than one match in a line, each of them is shown separately. This option is
+mutually exclusive with \fB--file-offsets\fP and \fB--only-matching\fP.
+.TP
+\fB--locale\fP=\fIlocale-name\fP
+This option specifies a locale to be used for pattern matching. It overrides
+the value in the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variables. If no
+locale is specified, the PCRE library's default (usually the "C" locale) is
+used. There is no short form for this option.
+.TP
+\fB-M\fP, \fB--multiline\fP
+Allow patterns to match more than one line. When this option is given, patterns
+may usefully contain literal newline characters and internal occurrences of ^
+and $ characters. The output for any one match may consist of more than one
+line. When this option is set, the PCRE library is called in "multiline" mode.
+There is a limit to the number of lines that can be matched, imposed by the way
+that \fBpcregrep\fP buffers the input file as it scans it. However,
+\fBpcregrep\fP ensures that at least 8K characters or the rest of the document
+(whichever is the shorter) are available for forward matching, and similarly
+the previous 8K characters (or all the previous characters, if fewer than 8K)
+are guaranteed to be available for lookbehind assertions.
+.TP
+\fB-N\fP \fInewline-type\fP, \fB--newline=\fP\fInewline-type\fP
+The PCRE library supports five different conventions for indicating
+the ends of lines. They are the single-character sequences CR (carriage return)
+and LF (linefeed), the two-character sequence CRLF, an "anycrlf" convention,
+which recognizes any of the preceding three types, and an "any" convention, in
+which any Unicode line ending sequence is assumed to end a line. The Unicode
+sequences are the three just mentioned, plus VT (vertical tab, U+000B), FF
+(formfeed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and
+PS (paragraph separator, U+2029).
+.sp
+When the PCRE library is built, a default line-ending sequence is specified.
+This is normally the standard sequence for the operating system. Unless
+otherwise specified by this option, \fBpcregrep\fP uses the library's default.
+The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This
+makes it possible to use \fBpcregrep\fP on files that have come from other
+environments without having to modify their line endings. If the data that is
+being scanned does not agree with the convention set by this option,
+\fBpcregrep\fP may behave in strange ways.
+.TP
+\fB-n\fP, \fB--line-number\fP
+Precede each output line by its line number in the file, followed by a colon
+and a space for matching lines or a hyphen and a space for context lines. If
+the filename is also being output, it precedes the line number. This option is
+forced if \fB--line-offsets\fP is used.
+.TP
+\fB-o\fP, \fB--only-matching\fP
+Show only the part of the line that matched a pattern. In this mode, no
+context is shown. That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP options are
+ignored. If there is more than one match in a line, each of them is shown
+separately. If \fB-o\fP is combined with \fB-v\fP (invert the sense of the
+match to find non-matching lines), no output is generated, but the return code
+is set appropriately. This option is mutually exclusive with
+\fB--file-offsets\fP and \fB--line-offsets\fP.
+.TP
+\fB-q\fP, \fB--quiet\fP
+Work quietly, that is, display nothing except error messages. The exit
+status indicates whether or not any matches were found.
+.TP
+\fB-r\fP, \fB--recursive\fP
+If any given path is a directory, recursively scan the files it contains,
+taking note of any \fB--include\fP and \fB--exclude\fP settings. By default, a
+directory is read as a normal file; in some operating systems this gives an
+immediate end-of-file. This option is a shorthand for setting the \fB-d\fP
+option to "recurse".
+.TP
+\fB-s\fP, \fB--no-messages\fP
+Suppress error messages about non-existent or unreadable files. Such files are
+quietly skipped. However, the return code is still 2, even if matches were
+found in other files.
+.TP
+\fB-u\fP, \fB--utf-8\fP
+Operate in UTF-8 mode. This option is available only if PCRE has been compiled
+with UTF-8 support. Both patterns and subject lines must be valid strings of
+UTF-8 characters.
+.TP
+\fB-V\fP, \fB--version\fP
+Write the version numbers of \fBpcregrep\fP and the PCRE library that is being
+used to the standard error stream.
+.TP
+\fB-v\fP, \fB--invert-match\fP
+Invert the sense of the match, so that lines which do \fInot\fP match any of
+the patterns are the ones that are found.
+.TP
+\fB-w\fP, \fB--word-regex\fP, \fB--word-regexp\fP
+Force the patterns to match only whole words. This is equivalent to having \eb
+at the start and end of the pattern.
+.TP
+\fB-x\fP, \fB--line-regex\fP, \fB--line-regexp\fP
+Force the patterns to be anchored (each must start matching at the beginning of
+a line) and in addition, require them to match entire lines. This is
+equivalent to having ^ and $ characters at the start and end of each
+alternative branch in every pattern.
+.
+.
+.SH "ENVIRONMENT VARIABLES"
+.rs
+.sp
+The environment variables \fBLC_ALL\fP and \fBLC_CTYPE\fP are examined, in that
+order, for a locale. The first one that is set is used. This can be overridden
+by the \fB--locale\fP option. If no locale is set, the PCRE library's default
+(usually the "C" locale) is used.
+.
+.
+.SH "NEWLINES"
+.rs
+.sp
+The \fB-N\fP (\fB--newline\fP) option allows \fBpcregrep\fP to scan files with
+different newline conventions from the default. However, the setting of this
+option does not affect the way in which \fBpcregrep\fP writes information to
+the standard error and output streams. It uses the string "\en" in C
+\fBprintf()\fP calls to indicate newlines, relying on the C I/O library to
+convert this to an appropriate sequence if the output is sent to a file.
+.
+.
+.SH "OPTIONS COMPATIBILITY"
+.rs
+.sp
+The majority of short and long forms of \fBpcregrep\fP's options are the same
+as in the GNU \fBgrep\fP program. Any long option of the form
+\fB--xxx-regexp\fP (GNU terminology) is also available as \fB--xxx-regex\fP
+(PCRE terminology). However, the \fB--locale\fP, \fB-M\fP, \fB--multiline\fP,
+\fB-u\fP, and \fB--utf-8\fP options are specific to \fBpcregrep\fP.
+.
+.
+.SH "OPTIONS WITH DATA"
+.rs
+.sp
+There are four different ways in which an option with data can be specified.
+If a short form option is used, the data may follow immediately, or in the next
+command line item. For example:
+.sp
+  -f/some/file
+  -f /some/file
+.sp
+If a long form option is used, the data may appear in the same command line
+item, separated by an equals character, or (with one exception) it may appear
+in the next command line item. For example:
+.sp
+  --file=/some/file
+  --file /some/file
+.sp
+Note, however, that if you want to supply a file name beginning with ~ as data
+in a shell command, and have the shell expand ~ to a home directory, you must
+separate the file name from the option, because the shell does not treat ~
+specially unless it is at the start of an item.
+.P
+The exception to the above is the \fB--colour\fP (or \fB--color\fP) option,
+for which the data is optional. If this option does have data, it must be given
+in the first form, using an equals character. Otherwise it will be assumed that
+it has no data.
+.
+.
+.SH "MATCHING ERRORS"
+.rs
+.sp
+It is possible to supply a regular expression that takes a very long time to
+fail to match certain lines. Such patterns normally involve nested indefinite
+repeats, for example: (a+)*\ed when matched against a line of a's with no final
+digit. The PCRE matching function has a resource limit that causes it to abort
+in these circumstances. If this happens, \fBpcregrep\fP outputs an error
+message and the line that caused the problem to the standard error stream. If
+there are more than 20 such errors, \fBpcregrep\fP gives up.
+.
+.
+.SH DIAGNOSTICS
+.rs
+.sp
+Exit status is 0 if any matches were found, 1 if no matches were found, and 2
+for syntax errors and non-existent or inacessible files (even if matches were
+found in other files) or too many matching errors. Using the \fB-s\fP option to
+suppress error messages about inaccessble files does not affect the return
+code.
+.
+.
+.SH "SEE ALSO"
+.rs
+.sp
+\fBpcrepattern\fP(3), \fBpcretest\fP(1).
+.
+.
+.SH AUTHOR
+.rs
+.sp
+.nf
+Philip Hazel
+University Computing Service
+Cambridge CB2 3QH, England.
+.fi
+.
+.
+.SH REVISION
+.rs
+.sp
+.nf
+Last updated: 08 March 2008
+Copyright (c) 1997-2008 University of Cambridge.
+.fi