Regex: Add PCRE 8.32 in tools directory.
This commit is contained in:
Arkshine
679
tools/pcre/doc/pcregrep.1
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679
tools/pcre/doc/pcregrep.1
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.TH PCREGREP 1 "13 September 2012" "PCRE 8.32"
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.SH NAME
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pcregrep - a grep with Perl-compatible regular expressions.
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.SH SYNOPSIS
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.B pcregrep [options] [long options] [pattern] [path1 path2 ...]
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.
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.SH DESCRIPTION
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.rs
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.sp
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\fBpcregrep\fP searches files for character patterns, in the same way as other
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grep commands do, but it uses the PCRE regular expression library to support
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patterns that are compatible with the regular expressions of Perl 5. See
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.\" HREF
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\fBpcrepattern\fP(3)
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.\"
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for a full description of syntax and semantics of the regular expressions
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that PCRE supports.
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.P
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Patterns, whether supplied on the command line or in a separate file, are given
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without delimiters. For example:
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.sp
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pcregrep Thursday /etc/motd
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.sp
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If you attempt to use delimiters (for example, by surrounding a pattern with
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slashes, as is common in Perl scripts), they are interpreted as part of the
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pattern. Quotes can of course be used to delimit patterns on the command line
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because they are interpreted by the shell, and indeed quotes are required if a
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pattern contains white space or shell metacharacters.
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.P
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The first argument that follows any option settings is treated as the single
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pattern to be matched when neither \fB-e\fP nor \fB-f\fP is present.
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Conversely, when one or both of these options are used to specify patterns, all
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arguments are treated as path names. At least one of \fB-e\fP, \fB-f\fP, or an
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argument pattern must be provided.
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.P
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If no files are specified, \fBpcregrep\fP reads the standard input. The
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standard input can also be referenced by a name consisting of a single hyphen.
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For example:
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.sp
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pcregrep some-pattern /file1 - /file3
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.sp
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By default, each line that matches a pattern is copied to the standard
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output, and if there is more than one file, the file name is output at the
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start of each line, followed by a colon. However, there are options that can
|
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change how \fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it
|
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possible to search for patterns that span line boundaries. What defines a line
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boundary is controlled by the \fB-N\fP (\fB--newline\fP) option.
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.P
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The amount of memory used for buffering files that are being scanned is
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controlled by a parameter that can be set by the \fB--buffer-size\fP option.
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The default value for this parameter is specified when \fBpcregrep\fP is built,
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with the default default being 20K. A block of memory three times this size is
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used (to allow for buffering "before" and "after" lines). An error occurs if a
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line overflows the buffer.
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.P
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Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater.
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BUFSIZ is defined in \fB<stdio.h>\fP. When there is more than one pattern
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(specified by the use of \fB-e\fP and/or \fB-f\fP), each pattern is applied to
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each line in the order in which they are defined, except that all the \fB-e\fP
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patterns are tried before the \fB-f\fP patterns.
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.P
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By default, as soon as one pattern matches a line, no further patterns are
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considered. However, if \fB--colour\fP (or \fB--color\fP) is used to colour the
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matching substrings, or if \fB--only-matching\fP, \fB--file-offsets\fP, or
|
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\fB--line-offsets\fP is used to output only the part of the line that matched
|
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(either shown literally, or as an offset), scanning resumes immediately
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following the match, so that further matches on the same line can be found. If
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there are multiple patterns, they are all tried on the remainder of the line,
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but patterns that follow the one that matched are not tried on the earlier part
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of the line.
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.P
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This behaviour means that the order in which multiple patterns are specified
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can affect the output when one of the above options is used. This is no longer
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the same behaviour as GNU grep, which now manages to display earlier matches
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for later patterns (as long as there is no overlap).
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.P
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Patterns that can match an empty string are accepted, but empty string
|
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matches are never recognized. An example is the pattern "(super)?(man)?", in
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which all components are optional. This pattern finds all occurrences of both
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"super" and "man"; the output differs from matching with "super|man" when only
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the matching substrings are being shown.
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.P
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If the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variable is set,
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\fBpcregrep\fP uses the value to set a locale when calling the PCRE library.
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The \fB--locale\fP option can be used to override this.
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.
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.
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.SH "SUPPORT FOR COMPRESSED FILES"
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.rs
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.sp
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It is possible to compile \fBpcregrep\fP so that it uses \fBlibz\fP or
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\fBlibbz2\fP to read files whose names end in \fB.gz\fP or \fB.bz2\fP,
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respectively. You can find out whether your binary has support for one or both
|
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of these file types by running it with the \fB--help\fP option. If the
|
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appropriate support is not present, files are treated as plain text. The
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standard input is always so treated.
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.
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.
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.SH "BINARY FILES"
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.rs
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.sp
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By default, a file that contains a binary zero byte within the first 1024 bytes
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is identified as a binary file, and is processed specially. (GNU grep also
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identifies binary files in this manner.) See the \fB--binary-files\fP option
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for a means of changing the way binary files are handled.
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.
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.
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.SH OPTIONS
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.rs
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.sp
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The order in which some of the options appear can affect the output. For
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example, both the \fB-h\fP and \fB-l\fP options affect the printing of file
|
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names. Whichever comes later in the command line will be the one that takes
|
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effect. Similarly, except where noted below, if an option is given twice, the
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later setting is used. Numerical values for options may be followed by K or M,
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to signify multiplication by 1024 or 1024*1024 respectively.
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.TP 10
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\fB--\fP
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This terminates the list of options. It is useful if the next item on the
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command line starts with a hyphen but is not an option. This allows for the
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processing of patterns and filenames that start with hyphens.
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.TP
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\fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP
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Output \fInumber\fP lines of context after each matching line. If filenames
|
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and/or line numbers are being output, a hyphen separator is used instead of a
|
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colon for the context lines. A line containing "--" is output between each
|
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group of lines, unless they are in fact contiguous in the input file. The value
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of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
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guarantees to have up to 8K of following text available for context output.
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.TP
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\fB-a\fP, \fB--text\fP
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Treat binary files as text. This is equivalent to
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\fB--binary-files\fP=\fItext\fP.
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.TP
|
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\fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP
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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
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guarantees to have up to 8K of preceding text available for context output.
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.TP
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\fB--binary-files=\fP\fIword\fP
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Specify how binary files are to be processed. If the word is "binary" (the
|
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default), pattern matching is performed on binary files, but the only output is
|
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"Binary file <name> matches" when a match succeeds. If the word is "text",
|
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which is equivalent to the \fB-a\fP or \fB--text\fP option, binary files are
|
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processed in the same way as any other file. In this case, when a match
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succeeds, the output may be binary garbage, which can have nasty effects if
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sent to a terminal. If the word is "without-match", which is equivalent to the
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\fB-I\fP option, binary files are not processed at all; they are assumed not to
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be of interest.
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.TP
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\fB--buffer-size=\fP\fInumber\fP
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Set the parameter that controls how much memory is used for buffering files
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that are being scanned.
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.TP
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\fB-C\fP \fInumber\fP, \fB--context=\fP\fInumber\fP
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Output \fInumber\fP lines of context both before and after each matching line.
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This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value.
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.TP
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\fB-c\fP, \fB--count\fP
|
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Do not output individual lines from the files that are being scanned; instead
|
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output the number of lines that would otherwise have been shown. If no lines
|
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are selected, the number zero is output. If several files are are being
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scanned, a count is output for each of them. However, if the
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\fB--files-with-matches\fP option is also used, only those files whose counts
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are greater than zero are listed. When \fB-c\fP is used, the \fB-A\fP,
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\fB-B\fP, and \fB-C\fP options are ignored.
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.TP
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\fB--colour\fP, \fB--color\fP
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If this option is given without any data, it is equivalent to "--colour=auto".
|
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If data is required, it must be given in the same shell item, separated by an
|
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equals sign.
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.TP
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\fB--colour=\fP\fIvalue\fP, \fB--color=\fP\fIvalue\fP
|
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This option specifies under what circumstances the parts of a line that matched
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a pattern should be coloured in the output. By default, the output is not
|
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coloured. The value (which is optional, see above) may be "never", "always", or
|
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"auto". In the latter case, colouring happens only if the standard output is
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connected to a terminal. More resources are used when colouring is enabled,
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because \fBpcregrep\fP has to search for all possible matches in a line, not
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just one, in order to colour them all.
|
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.sp
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The colour that is used can be specified by setting the environment variable
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PCREGREP_COLOUR or PCREGREP_COLOR. The value of this variable should be a
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string of two numbers, separated by a semicolon. They are copied directly into
|
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the control string for setting colour on a terminal, so it is your
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responsibility to ensure that they make sense. If neither of the environment
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variables is set, the default is "1;31", which gives red.
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.TP
|
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\fB-D\fP \fIaction\fP, \fB--devices=\fP\fIaction\fP
|
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If an input path is not a regular file or a directory, "action" specifies how
|
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it is to be processed. Valid values are "read" (the default) or "skip"
|
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(silently skip the path).
|
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.TP
|
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\fB-d\fP \fIaction\fP, \fB--directories=\fP\fIaction\fP
|
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If an input path is a directory, "action" specifies how it is to be processed.
|
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Valid values are "read" (the default in non-Windows environments, for
|
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compatibility with GNU grep), "recurse" (equivalent to the \fB-r\fP option), or
|
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"skip" (silently skip the path, the default in Windows environments). In the
|
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"read" case, directories are read as if they were ordinary files. In some
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operating systems the effect of reading a directory like this is an immediate
|
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end-of-file; in others it may provoke an error.
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.TP
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\fB-e\fP \fIpattern\fP, \fB--regex=\fP\fIpattern\fP, \fB--regexp=\fP\fIpattern\fP
|
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Specify a pattern to be matched. This option can be used multiple times in
|
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order to specify several patterns. It can also be used as a way of specifying a
|
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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 no limit to the number of patterns. They are applied to each
|
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line in the order in which they are defined until one matches.
|
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.sp
|
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If \fB-f\fP is used with \fB-e\fP, the command line patterns are matched first,
|
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followed by the patterns from the file(s), independent of the order in which
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these options are specified. Note that multiple use of \fB-e\fP is not the same
|
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as a single pattern with alternatives. For example, X|Y finds the first
|
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character in a line that is X or Y, whereas if the two patterns are given
|
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separately, with X first, \fBpcregrep\fP finds X if it is present, even if it
|
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follows Y in the line. It finds Y only if there is no X in the line. This
|
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matters only if you are using \fB-o\fP or \fB--colo(u)r\fP to show the part(s)
|
||||
of the line that matched.
|
||||
.TP
|
||||
\fB--exclude\fP=\fIpattern\fP
|
||||
Files (but not directories) whose names match the pattern are skipped without
|
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being processed. This applies to all files, whether listed on the command line,
|
||||
obtained from \fB--file-list\fP, or by scanning a directory. The pattern is a
|
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PCRE regular expression, and is matched against the final component of the file
|
||||
name, not the entire path. The \fB-F\fP, \fB-w\fP, and \fB-x\fP options do not
|
||||
apply to this pattern. The option may be given any number of times in order to
|
||||
specify multiple patterns. If a file name matches both an \fB--include\fP
|
||||
and an \fB--exclude\fP pattern, it is excluded. There is no short form for this
|
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option.
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.TP
|
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\fB--exclude-from=\fP\fIfilename\fP
|
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Treat each non-empty line of the file as the data for an \fB--exclude\fP
|
||||
option. What constitutes a newline when reading the file is the operating
|
||||
system's default. The \fB--newline\fP option has no effect on this option. This
|
||||
option may be given more than once in order to specify a number of files to
|
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read.
|
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.TP
|
||||
\fB--exclude-dir\fP=\fIpattern\fP
|
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Directories whose names match the pattern are skipped without being processed,
|
||||
whatever the setting of the \fB--recursive\fP option. This applies to all
|
||||
directories, whether listed on the command line, obtained from
|
||||
\fB--file-list\fP, or by scanning a parent directory. The pattern is a PCRE
|
||||
regular expression, and is matched against the final component of the directory
|
||||
name, not the entire path. The \fB-F\fP, \fB-w\fP, and \fB-x\fP options do not
|
||||
apply to this pattern. The option may be given any number of times in order to
|
||||
specify more than one pattern. If a directory 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 data-matching pattern as a list of fixed strings, separated by
|
||||
newlines, instead of as a regular expression. What constitutes a newline for
|
||||
this purpose is controlled by the \fB--newline\fP option. 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). This
|
||||
option applies only to the patterns that are matched against the contents of
|
||||
files; it does not apply to patterns specified by any of the \fB--include\fP or
|
||||
\fB--exclude\fP options.
|
||||
.TP
|
||||
\fB-f\fP \fIfilename\fP, \fB--file=\fP\fIfilename\fP
|
||||
Read patterns from the file, one per line, and match them against
|
||||
each line of input. What constitutes a newline when reading the file is the
|
||||
operating system's default. The \fB--newline\fP option has no effect on this
|
||||
option. 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.
|
||||
.sp
|
||||
If this option is given more than once, all the specified files are
|
||||
read. A data line is output if any of the patterns match it. A 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 the names of paths to be searched.
|
||||
.TP
|
||||
\fB--file-list\fP=\fIfilename\fP
|
||||
Read a list of files and/or directories that are to be scanned from the given
|
||||
file, one per line. Trailing white space is removed from each line, and blank
|
||||
lines are ignored. These paths are processed before any that are listed on the
|
||||
command line. The filename can be given as "-" to refer to the standard input.
|
||||
If \fB--file\fP and \fB--file-list\fP are both specified as "-", patterns are
|
||||
read first. This is useful only when the standard input is a terminal, from
|
||||
which further lines (the list of files) can be read after an end-of-file
|
||||
indication. If this option is given more than once, all the specified files are
|
||||
read.
|
||||
.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; for context lines, a hyphen
|
||||
separator is used. If a line number is also being output, it follows the file
|
||||
name.
|
||||
.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; for context lines, a hyphen separator is used.
|
||||
If a line number is also being output, it follows the file name.
|
||||
.TP
|
||||
\fB--help\fP
|
||||
Output a help message, giving brief details of the command options and file
|
||||
type support, and then exit. Anything else on the command line is
|
||||
ignored.
|
||||
.TP
|
||||
\fB-I\fP
|
||||
Treat binary files as never matching. This is equivalent to
|
||||
\fB--binary-files\fP=\fIwithout-match\fP.
|
||||
.TP
|
||||
\fB-i\fP, \fB--ignore-case\fP
|
||||
Ignore upper/lower case distinctions during comparisons.
|
||||
.TP
|
||||
\fB--include\fP=\fIpattern\fP
|
||||
If any \fB--include\fP patterns are specified, the only files that are
|
||||
processed are those that match one of the patterns (and do not match an
|
||||
\fB--exclude\fP pattern). This option does not affect directories, but it
|
||||
applies to all files, whether listed on the command line, obtained from
|
||||
\fB--file-list\fP, or by scanning a directory. The pattern is a PCRE regular
|
||||
expression, and is matched against the final component of the file name, not
|
||||
the entire path. The \fB-F\fP, \fB-w\fP, and \fB-x\fP options do not apply to
|
||||
this pattern. The option may be given any number of times. If a file name
|
||||
matches both an \fB--include\fP and an \fB--exclude\fP pattern, it is excluded.
|
||||
There is no short form for this option.
|
||||
.TP
|
||||
\fB--include-from=\fP\fIfilename\fP
|
||||
Treat each non-empty line of the file as the data for an \fB--include\fP
|
||||
option. What constitutes a newline for this purpose is the operating system's
|
||||
default. The \fB--newline\fP option has no effect on this option. This option
|
||||
may be given any number of times; all the files are read.
|
||||
.TP
|
||||
\fB--include-dir\fP=\fIpattern\fP
|
||||
If any \fB--include-dir\fP patterns are specified, the only directories that
|
||||
are processed are those that match one of the patterns (and do not match an
|
||||
\fB--exclude-dir\fP pattern). This applies to all directories, whether listed
|
||||
on the command line, obtained from \fB--file-list\fP, or by scanning a parent
|
||||
directory. The pattern is a PCRE regular expression, and is matched against the
|
||||
final component of the directory name, not the entire path. The \fB-F\fP,
|
||||
\fB-w\fP, and \fB-x\fP options do not apply to this pattern. The option may be
|
||||
given any number of times. If a directory 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 normally stops as soon as a matching line
|
||||
is found in a file. However, if the \fB-c\fP (count) option is also used,
|
||||
matching continues in order to obtain the correct count, and those files that
|
||||
have at least one match are listed along with their counts. Using this option
|
||||
with \fB-c\fP is a way of suppressing the listing of files with no matches.
|
||||
.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-buffered\fP
|
||||
When this option is given, input is read and processed line by line, and the
|
||||
output is flushed after each write. By default, input is read in large chunks,
|
||||
unless \fBpcregrep\fP can determine that it is reading from a terminal (which
|
||||
is currently possible only in Unix-like environments). Output to terminal is
|
||||
normally automatically flushed by the operating system. This option can be
|
||||
useful when the input or output is attached to a pipe and you do not want
|
||||
\fBpcregrep\fP to buffer up large amounts of data. However, its use will affect
|
||||
performance, and the \fB-M\fP (multiline) option ceases to work.
|
||||
.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--match-limit\fP=\fInumber\fP
|
||||
Processing some regular expression patterns can require a very large amount of
|
||||
memory, leading in some cases to a program crash if not enough is available.
|
||||
Other patterns may take a very long time to search for all possible matching
|
||||
strings. The \fBpcre_exec()\fP function that is called by \fBpcregrep\fP to do
|
||||
the matching has two parameters that can limit the resources that it uses.
|
||||
.sp
|
||||
The \fB--match-limit\fP option provides a means of limiting resource usage
|
||||
when processing patterns that are not going to match, but which have a very
|
||||
large number of possibilities in their search trees. The classic example is a
|
||||
pattern that uses nested unlimited repeats. Internally, PCRE uses a function
|
||||
called \fBmatch()\fP which it calls repeatedly (sometimes recursively). The
|
||||
limit set by \fB--match-limit\fP is imposed on the number of times this
|
||||
function is called during a match, which has the effect of limiting the amount
|
||||
of backtracking that can take place.
|
||||
.sp
|
||||
The \fB--recursion-limit\fP option is similar to \fB--match-limit\fP, but
|
||||
instead of limiting the total number of times that \fBmatch()\fP is called, it
|
||||
limits the depth of recursive calls, which in turn limits the amount of memory
|
||||
that can be used. The recursion depth is a smaller number than the total number
|
||||
of calls, because not all calls to \fBmatch()\fP are recursive. This limit is
|
||||
of use only if it is set smaller than \fB--match-limit\fP.
|
||||
.sp
|
||||
There are no short forms for these options. The default settings are specified
|
||||
when the PCRE library is compiled, with the default default being 10 million.
|
||||
.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 a successful match may consist of more than
|
||||
one line, the last of which is the one in which the match ended. If the matched
|
||||
string ends with a newline sequence the output ends at the end of that line.
|
||||
.sp
|
||||
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. This option does not
|
||||
work when input is read line by line (see \fP--line-buffered\fP.)
|
||||
.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
|
||||
(form feed, 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 to scan 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. Note that this option does not
|
||||
apply to files specified by the \fB-f\fP, \fB--exclude-from\fP, or
|
||||
\fB--include-from\fP options, which are expected to use the operating system's
|
||||
standard newline sequence.
|
||||
.TP
|
||||
\fB-n\fP, \fB--line-number\fP
|
||||
Precede each output line by its line number in the file, followed by a colon
|
||||
for matching lines or a hyphen 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--no-jit\fP
|
||||
If the PCRE library is built with support for just-in-time compiling (which
|
||||
speeds up matching), \fBpcregrep\fP automatically makes use of this, unless it
|
||||
was explicitly disabled at build time. This option can be used to disable the
|
||||
use of JIT at run time. It is provided for testing and working round problems.
|
||||
It should never be needed in normal use.
|
||||
.TP
|
||||
\fB-o\fP, \fB--only-matching\fP
|
||||
Show only the part of the line that matched a pattern instead of the whole
|
||||
line. 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. If the matched portion of the line is empty,
|
||||
nothing is output unless the file name or line number are being printed, in
|
||||
which case they are shown on an otherwise empty line. This option is mutually
|
||||
exclusive with \fB--file-offsets\fP and \fB--line-offsets\fP.
|
||||
.TP
|
||||
\fB-o\fP\fInumber\fP, \fB--only-matching\fP=\fInumber\fP
|
||||
Show only the part of the line that matched the capturing parentheses of the
|
||||
given number. Up to 32 capturing parentheses are supported, and -o0 is
|
||||
equivalent to \fB-o\fP without a number. Because these options can be given
|
||||
without an argument (see above), if an argument is present, it must be given in
|
||||
the same shell item, for example, -o3 or --only-matching=2. The comments given
|
||||
for the non-argument case above also apply to this case. If the specified
|
||||
capturing parentheses do not exist in the pattern, or were not set in the
|
||||
match, nothing is output unless the file name or line number are being printed.
|
||||
.sp
|
||||
If this option is given multiple times, multiple substrings are output, in the
|
||||
order the options are given. For example, -o3 -o1 -o3 causes the substrings
|
||||
matched by capturing parentheses 3 and 1 and then 3 again to be output. By
|
||||
default, there is no separator (but see the next option).
|
||||
.TP
|
||||
\fB--om-separator\fP=\fItext\fP
|
||||
Specify a separating string for multiple occurrences of \fB-o\fP. The default
|
||||
is an empty string. Separating strings are never coloured.
|
||||
.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--recursion-limit\fP=\fInumber\fP
|
||||
See \fB--match-limit\fP above.
|
||||
.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. All patterns (including those for any \fB--exclude\fP and
|
||||
\fB--include\fP options) and all subject lines that are scanned 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 to the
|
||||
standard output and then exit. Anything else on the command line is
|
||||
ignored.
|
||||
.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. This option applies only to the patterns
|
||||
that are matched against the contents of files; it does not apply to patterns
|
||||
specified by any of the \fB--include\fP or \fB--exclude\fP options.
|
||||
.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. This option applies only to the patterns that are matched
|
||||
against the contents of files; it does not apply to patterns specified by any
|
||||
of the \fB--include\fP or \fB--exclude\fP options.
|
||||
.
|
||||
.
|
||||
.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. Any parts of the input files
|
||||
that are written to the standard output are copied identically, with whatever
|
||||
newline sequences they have in the input. However, the setting of this option
|
||||
does not affect the interpretation of files specified by the \fB-f\fP,
|
||||
\fB--exclude-from\fP, or \fB--include-from\fP options, which are assumed to use
|
||||
the operating system's standard newline sequence, nor does it affect the way in
|
||||
which \fBpcregrep\fP writes informational messages to the standard error and
|
||||
output streams. For these it uses the string "\en" to indicate newlines,
|
||||
relying on the C I/O library to convert this to an appropriate sequence.
|
||||
.
|
||||
.
|
||||
.SH "OPTIONS COMPATIBILITY"
|
||||
.rs
|
||||
.sp
|
||||
Many of the 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--file-list\fP, \fB--file-offsets\fP,
|
||||
\fB--include-dir\fP, \fB--line-offsets\fP, \fB--locale\fP, \fB--match-limit\fP,
|
||||
\fB-M\fP, \fB--multiline\fP, \fB-N\fP, \fB--newline\fP, \fB--om-separator\fP,
|
||||
\fB--recursion-limit\fP, \fB-u\fP, and \fB--utf-8\fP options are specific to
|
||||
\fBpcregrep\fP, as is the use of the \fB--only-matching\fP option with a
|
||||
capturing parentheses number.
|
||||
.P
|
||||
Although most of the common options work the same way, a few are different in
|
||||
\fBpcregrep\fP. For example, the \fB--include\fP option's argument is a glob
|
||||
for GNU \fBgrep\fP, but a regular expression for \fBpcregrep\fP. If both the
|
||||
\fB-c\fP and \fB-l\fP options are given, GNU grep lists only file names,
|
||||
without counts, but \fBpcregrep\fP gives the counts.
|
||||
.
|
||||
.
|
||||
.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 (with one
|
||||
exception) in the next command line item. For example:
|
||||
.sp
|
||||
-f/some/file
|
||||
-f /some/file
|
||||
.sp
|
||||
The exception is the \fB-o\fP option, which may appear with or without data.
|
||||
Because of this, if data is present, it must follow immediately in the same
|
||||
item, for example -o3.
|
||||
.P
|
||||
If a long form option is used, the data may appear in the same command line
|
||||
item, separated by an equals character, or (with two exceptions) 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 exceptions to the above are the \fB--colour\fP (or \fB--color\fP) and
|
||||
\fB--only-matching\fP options, for which the data is optional. If one of these
|
||||
options does have data, it must be given in the first form, using an equals
|
||||
character. Otherwise \fBpcregrep\fP will assume 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.
|
||||
.P
|
||||
The \fB--match-limit\fP option of \fBpcregrep\fP can be used to set the overall
|
||||
resource limit; there is a second option called \fB--recursion-limit\fP that
|
||||
sets a limit on the amount of memory (usually stack) that is used (see the
|
||||
discussion of these options above).
|
||||
.
|
||||
.
|
||||
.SH DIAGNOSTICS
|
||||
.rs
|
||||
.sp
|
||||
Exit status is 0 if any matches were found, 1 if no matches were found, and 2
|
||||
for syntax errors, overlong lines, non-existent or inaccessible 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 inaccessible files does not
|
||||
affect the return code.
|
||||
.
|
||||
.
|
||||
.SH "SEE ALSO"
|
||||
.rs
|
||||
.sp
|
||||
\fBpcrepattern\fP(3), \fBpcresyntax\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: 13 September 2012
|
||||
Copyright (c) 1997-2012 University of Cambridge.
|
||||
.fi
|
||||
Reference in New Issue
Block a user