This terminates 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 file names that start with hyphens.

Output number lines of context after each matching line. If file names 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 number is expected to be relatively small. However, pcre2grep guarantees to have up to 8K of following text available for context output.

Treat binary files as text. This is equivalent to −−binary−files=text.

Output number lines of context before each matching line. If file names 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 number is expected to be relatively small. However, pcre2grep guarantees to have up to 8K of preceding text available for context output.

Specify how binary files are to be processed. If the word is "binary" (the default), pattern matching is performed on binary files, but the only output is "Binary file <name> matches" when a match succeeds. If the word is "text", which is equivalent to the −a or −−text option, binary files are processed in the same way as any other file. In this case, when a match succeeds, the output may be binary garbage, which can have nasty effects if sent to a terminal. If the word is "without-match", which is equivalent to the −I option, binary files are not processed at all; they are assumed not to be of interest and are skipped without causing any output or affecting the return code.

Set the parameter that controls how much memory is used for buffering files that are being scanned.

Output number lines of context both before and after each matching line. This is equivalent to setting both −A and −B to the same value.

Do not output lines from the files that are being scanned; instead output the number of matches (or non-matches if −v is used) that would otherwise have caused lines to be shown. By default, this count is the same as the number of suppressed lines, but if the −M (multiline) option is used (without −v), there may be more suppressed lines than the number of matches.

If no lines are selected, the number zero is output. If several files are are being scanned, a count is output for each of them. However, if the −−files−with−matches option is also used, only those files whose counts are greater than zero are listed. When −c is used, the −A, −B, and −C options are ignored.

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.

This option specifies under what circumstances the parts of a line that matched a pattern should be coloured in the output. By default, the output is not coloured. The value (which is optional, see above) may be "never", "always", or "auto". In the latter case, colouring happens only if the standard output is connected to a terminal. More resources are used when colouring is enabled, because pcre2grep has to search for all possible matches in a line, not just one, in order to colour them all.

The colour that is used can be specified by setting the environment variable PCRE2GREP_COLOUR or PCRE2GREP_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.

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).

If an input path is a directory, "action" specifies how it is to be processed. Valid values are "read" (the default in non-Windows environments, for compatibility with GNU grep), "recurse" (equivalent to the −r option), or "skip" (silently skip the path, the default in Windows environments). In the "read" 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; in others it may provoke an error.

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 −e 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 line in the order in which they are defined until one matches.

If −f is used with −e, the command line patterns are matched first, followed by the patterns from the file(s), independent of the order in which these options are specified. Note that multiple use of −e 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, with X first, pcre2grep 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 matters only if you are using −o or −−colo(u)r to show the part(s) of the line that matched.

Files (but not directories) whose names match the pattern are skipped without being processed. This applies to all files, whether listed on the command line, obtained from −−file−list, or by scanning a directory. The pattern is a PCRE2 regular expression, and is matched against the final component of the file name, not the entire path. The −F, −w, and −x 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 −−include and an −−exclude pattern, it is excluded. There is no short form for this option.

Treat each non-empty line of the file as the data for an −−exclude option. What constitutes a newline when reading the file is the operating system's default. The −−newline option has no effect on this option. This option may be given more than once in order to specify a number of files to read.

Directories whose names match the pattern are skipped without being processed, whatever the setting of the −−recursive option. This applies to all directories, whether listed on the command line, obtained from −−file−list, or by scanning a parent directory. The pattern is a PCRE2 regular expression, and is matched against the final component of the directory name, not the entire path. The −F, −w, and −x 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 −−include−dir and −−exclude−dir, it is excluded. There is no short form for this option.

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 −−newline option. The −w (match as a word) and −x (match whole line) options can be used with −F. They apply to each of the fixed strings. A line is selected if any of the fixed strings are found in it (subject to −w or −x, 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 −−include or −−exclude options.

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 −−newline 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 −e above.

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 file name can be given as "-" to refer to the standard input. When −f is used, patterns specified on the command line using −e 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.

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 file name can be given as "-" to refer to the standard input. If −−file and −−file−list 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.

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 −A, −B, and −C 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 −−line−offsets and −−only−matching.

Force the inclusion of the file name at the start of output lines when searching a single file. By default, the file name is not shown in this case. For matching lines, the file name 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. When the −M option causes a pattern to match more than one line, only the first is preceded by the file name.

Suppress the output file names when searching multiple files. By default, file names are shown when multiple files are searched. For matching lines, the file name 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.

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.

Ignore binary files. This is equivalent to −−binary−files=without-match.

Ignore upper/lower case distinctions during comparisons.

If any −−include patterns are specified, the only files that are processed are those that match one of the patterns (and do not match an −−exclude pattern). This option does not affect directories, but it applies to all files, whether listed on the command line, obtained from −−file−list, or by scanning a directory. The pattern is a PCRE2 regular expression, and is matched against the final component of the file name, not the entire path. The −F, −w, and −x options do not apply to this pattern. The option may be given any number of times. If a file name matches both an −−include and an −−exclude pattern, it is excluded. There is no short form for this option.

Treat each non-empty line of the file as the data for an −−include option. What constitutes a newline for this purpose is the operating system's default. The −−newline option has no effect on this option. This option may be given any number of times; all the files are read.

If any −−include−dir patterns are specified, the only directories that are processed are those that match one of the patterns (and do not match an −−exclude−dir pattern). This applies to all directories, whether listed on the command line, obtained from −−file−list, or by scanning a parent directory. The pattern is a PCRE2 regular expression, and is matched against the final component of the directory name, not the entire path. The −F, −w, and −x options do not apply to this pattern. The option may be given any number of times. If a directory matches both −−include−dir and −−exclude−dir, it is excluded. There is no short form for this option.

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.

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 −c (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 −c is a way of suppressing the listing of files with no matches.

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.

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 pcre2grep 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 pcre2grep to buffer up large amounts of data. However, its use will affect performance, and the −M (multiline) option ceases to work.

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 −n option), and the offset and length are separated by a comma. In this mode, no context is shown. That is, the −A, −B, and −C 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 −−file−offsets and −−only−matching.

This option specifies a locale to be used for pattern matching. It overrides the value in the LC_ALL or LC_CTYPE environment variables. If no locale is specified, the PCRE2 library's default (usually the "C" locale) is used. There is no short form for this option.

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 pcre2_match() function that is called by pcre2grep to do the matching has two parameters that can limit the resources that it uses.

The −−match−limit 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, PCRE2 uses a function called match() which it calls repeatedly (sometimes recursively). The limit set by −−match−limit 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.

The −−recursion−limit option is similar to −−match−limit, but instead of limiting the total number of times that match() 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 match() are recursive. This limit is of use only if it is set smaller than −−match−limit.

There are no short forms for these options. The default settings are specified when the PCRE2 library is compiled, with the default default being 10 million.

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 first is the line in which the match started, and the last is the line in which the match ended. If the matched string ends with a newline sequence the output ends at the end of that line.

When this option is set, the PCRE2 library is called in "multiline" mode. This allows a matched string to extend past the end of a line and continue on one or more subsequent lines. However, pcre2grep still processes the input line by line. Once a match has been handled, scanning restarts at the beginning of the next line, just as it does when −M is not present. This means that it is possible for the second or subsequent lines in a multiline match to be output again as part of another match.

The newline sequence that separates multiple lines must be matched as part of the pattern. For example, to find the phrase "regular expression" in a file where "regular" might be at the end of a line and "expression" at the start of the next line, you could use this command:

pcre2grep -M 'regular\s+expression' <file>

The \s escape sequence matches any white space character, including newlines, and is followed by + so as to match trailing white space on the first line as well as possibly handling a two-character newline sequence.

There is a limit to the number of lines that can be matched, imposed by the way that pcre2grep buffers the input file as it scans it. However, pcre2grep ensures that at least 8K characters or the rest of the file (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. The −M option does not work when input is read line by line (see −−line−buffered.)

The PCRE2 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).

When the PCRE2 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, pcre2grep uses the library's default. The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This makes it possible to use pcre2grep 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, pcre2grep may behave in strange ways. Note that this option does not apply to files specified by the −f, −−exclude−from, or −−include−from options, which are expected to use the operating system's standard newline sequence.

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 file name is also being output, it precedes the line number. When the −M option causes a pattern to match more than one line, only the first is preceded by its line number. This option is forced if −−line−offsets is used.

If the PCRE2 library is built with support for just-in-time compiling (which speeds up matching), pcre2grep 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.

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 −A, −B, and −C options are ignored. If there is more than one match in a line, each of them is shown separately. If −o is combined with −v (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 −−file−offsets and −−line−offsets.

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 −o 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 output.

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).

Specify a separating string for multiple occurrences of −o. The default is an empty string. Separating strings are never coloured.

Work quietly, that is, display nothing except error messages. The exit status indicates whether or not any matches were found.

If any given path is a directory, recursively scan the files it contains, taking note of any −−include and −−exclude 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 −d option to "recurse".

See −−match−limit above.

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.

Operate in UTF-8 mode. This option is available only if PCRE2 has been compiled with UTF-8 support. All patterns (including those for any −−exclude and −−include options) and all subject lines that are scanned must be valid strings of UTF-8 characters.

Write the version numbers of pcre2grep and the PCRE2 library to the standard output and then exit. Anything else on the command line is ignored.

Invert the sense of the match, so that lines which do not match any of the patterns are the ones that are found.

Force the patterns to match only whole words. This is equivalent to having \b 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 −−include or −−exclude options.

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 top-level 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 −−include or −−exclude options.