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OpenSolaris 2009.06 - man page for pcretest (opensolaris section 1)

PCRETEST(1)			     General Commands Manual			      PCRETEST(1)

       pcretest - a program for testing Perl-compatible regular expressions.


       pcretest [options] [source] [destination]

       pcretest was written as a test program for the PCRE regular expression library itself, but
       it can also be used for experimenting with regular expressions.	This  document	describes
       the  features  of the test program; for details of the regular expressions themselves, see
       the pcrepattern documentation. For details of the PCRE library function	calls  and  their
       options, see the pcreapi documentation.


       -b	 Behave  as  if each regex has the /B (show bytecode) modifier; the internal form
		 is output after compilation.

       -C	 Output the version number of the PCRE library,  and  all  available  information
		 about the optional features that are included, and then exit.

       -d	 Behave  as  if  each  regex  has  the /D (debug) modifier; the internal form and
		 information about the compiled pattern is output after compilation; -d is equiv-
		 alent to -b -i.

       -dfa	 Behave  as  if  each  data line contains the \D escape sequence; this causes the
		 alternative matching function, pcre_dfa_exec(), to be used instead of the  stan-
		 dard pcre_exec() function (more detail is given below).

       -help	 Output a brief summary these options and then exit.

       -i	 Behave as if each regex has the /I modifier; information about the compiled pat-
		 tern is given after compilation.

       -m	 Output the size of each compiled pattern after it has	been  compiled.  This  is
		 equivalent  to adding /M to each regular expression. For compatibility with ear-
		 lier versions of pcretest, -s is a synonym for -m.

       -o osize  Set the number of elements in the  output  vector  that  is  used  when  calling
		 pcre_exec()  or  pcre_dfa_exec()  to be osize. The default value is 45, which is
		 enough for 14 capturing subexpressions for pcre_exec() or 22  different  matches
		 for  pcre_dfa_exec().	The  vector  size  can be changed for individual matching
		 calls by including \O in the data line (see below).

       -p	 Behave as if each regex has the /P modifier; the POSIX wrapper API  is  used  to
		 call PCRE. None of the other options has any effect when -p is set.

       -q	 Do not output the version number of pcretest at the start of execution.

       -S size	 On Unix-like systems, set the size of the runtime stack to size megabytes.

       -t	 Run each compile, study, and match many times with a timer, and output resulting
		 time per compile or match (in milliseconds). Do not set -m with -t, because  you
		 will then get the size output a zillion times, and the timing will be distorted.
		 You can control the number of iterations that are used for timing  by	following
		 -t  with  a  number  (as  a separate item on the command line). For example, "-t
		 1000" would iterate 1000 times. The default is to iterate 500000 times.

       -tm	 This is like -t except that it times only the matching phase, not the compile or
		 study phases.


       If  pcretest  is  given	two filename arguments, it reads from the first and writes to the
       second. If it is given only one filename argument, it reads from that file and  writes  to
       stdout.	Otherwise, it reads from stdin and writes to stdout, and prompts for each line of
       input, using "re>" to prompt for regular expressions,  and  "data>"  to	prompt	for  data

       When  pcretest  is built, a configuration option can specify that it should be linked with
       the libreadline library. When this is done, if the input is from a terminal,  it  is  read
       using the readline() function. This provides line-editing and history facilities. The out-
       put from the -help option states whether or not readline() will be used.

       The program handles any number of sets of input on a single input file.	Each  set  starts
       with  a	regular  expression,  and  continues  with any number of data lines to be matched
       against the pattern.

       Each data line is matched separately and independently.	If  you  want  to  do  multi-line
       matches,  you  have  to	use the \n escape sequence (or \r or \r\n, etc., depending on the
       newline setting) in a single line of input to encode the newline sequences.  There  is  no
       limit on the length of data lines; the input buffer is automatically extended if it is too

       An empty line signals the end of the data lines, at which point a new  regular  expression
       is  read.  The  regular	expressions are given enclosed in any non-alphanumeric delimiters
       other than backslash, for example:


       White space before the initial delimiter is ignored. A regular expression may be continued
       over  several input lines, in which case the newline characters are included within it. It
       is possible to include the delimiter within the pattern by escaping it, for example


       If you do so, the escape and the delimiter form part of the pattern, but since  delimiters
       are  always non-alphanumeric, this does not affect its interpretation.  If the terminating
       delimiter is immediately followed by a backslash, for example,


       then a backslash is added to the end of the pattern. This is done  to  provide  a  way  of
       testing the error condition that arises if a pattern finishes with a backslash, because


       is interpreted as the first line of a pattern that starts with "abc/", causing pcretest to
       read the next line as a continuation of the regular expression.


       A pattern may be followed by any number of modifiers, which are mostly single  characters.
       Following Perl usage, these are referred to below as, for example, "the /i modifier", even
       though the delimiter of the pattern need not always be a slash, and no slash is used  when
       writing modifiers. Whitespace may appear between the final pattern delimiter and the first
       modifier, and between the modifiers themselves.

       The /i, /m, /s, and /x modifiers set the PCRE_CASELESS,	PCRE_MULTILINE,  PCRE_DOTALL,  or
       PCRE_EXTENDED  options,	respectively,  when pcre_compile() is called. These four modifier
       letters have the same effect as they do in Perl. For example:


       The following table shows additional modifiers for setting PCRE options that do not corre-
       spond to anything in Perl:

	 /<bsr_anycrlf>  PCRE_BSR_ANYCRLF
	 /<bsr_unicode>  PCRE_BSR_UNICODE

       Those  specifying  line ending sequences are literal strings as shown, but the letters can
       be in either case. This example sets multiline matching	with  CRLF  as	the  line  ending


       Details of the meanings of these PCRE options are given in the pcreapi documentation.

   Finding all matches in a string

       Searching  for  all possible matches within each subject string can be requested by the /g
       or /G modifier. After finding a match, PCRE is called again to search the remainder of the
       subject	string.  The difference between /g and /G is that the former uses the startoffset
       argument to pcre_exec() to start searching at a new point within the entire string  (which
       is  in  effect what Perl does), whereas the latter passes over a shortened substring. This
       makes a difference to the matching process if the pattern begins with a lookbehind  asser-
       tion (including \b or \B).

       If  any	call to pcre_exec() in a /g or /G sequence matches an empty string, the next call
       is done with the PCRE_NOTEMPTY and PCRE_ANCHORED flags set in order to search for another,
       non-empty,  match  at  the  same  point.   If this second match fails, the start offset is
       advanced by one, and the normal match is retried. This imitates the way Perl handles  such
       cases when using the /g modifier or the split() function.

   Other modifiers

       There are yet more modifiers for controlling the way pcretest operates.

       The  /+ modifier requests that as well as outputting the substring that matched the entire
       pattern, pcretest should in addition output the remainder of the subject string.  This  is
       useful for tests where the subject contains multiple copies of the same substring.

       The  /B modifier is a debugging feature. It requests that pcretest output a representation
       of the compiled byte code after compilation. Normally this information contains length and
       offset  values; however, if /Z is also present, this data is replaced by spaces. This is a
       special feature for use in the automatic test scripts; it ensures that the same output  is
       generated for different internal link sizes.

       The /L modifier must be followed directly by the name of a locale, for example,


       For  this reason, it must be the last modifier. The given locale is set, pcre_maketables()
       is called to build a set of character tables for the locale, and this is  then  passed  to
       pcre_compile()  when  compiling	the  regular  expression. Without an /L modifier, NULL is
       passed as the tables pointer; that is, /L applies only  to  the	expression  on	which  it

       The  /I	modifier  requests  that  pcretest  output information about the compiled pattern
       (whether it is anchored, has a fixed first character, and so on). It does this by  calling
       pcre_fullinfo()	after compiling a pattern. If the pattern is studied, the results of that
       are also output.

       The /D modifier is a PCRE debugging feature, and is equivalent to /BI, that is,	both  the
       /B and the /I modifiers.

       The  /F modifier causes pcretest to flip the byte order of the fields in the compiled pat-
       tern that contain 2-byte and 4-byte numbers. This facility is for testing the  feature  in
       PCRE  that  allows  it  to  execute patterns that were compiled on a host with a different
       endianness. This feature is not available when the POSIX interface to PCRE is being  used,
       that  is, when the /P pattern modifier is specified. See also the section about saving and
       reloading compiled patterns below.

       The /S modifier causes pcre_study() to be called after the expression has  been	compiled,
       and the results used when the expression is matched.

       The  /M	modifier  causes the size of memory block used to hold the compiled pattern to be

       The /P modifier causes pcretest to call PCRE via the POSIX wrapper  API	rather	than  its
       native  API.  When  this  is  done, all other modifiers except /i, /m, and /+ are ignored.
       REG_ICASE is set if /i is present, and REG_NEWLINE is set if /m is  present.  The  wrapper
       functions force PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is set.

       The  /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option set. This turns on
       support for UTF-8 character handling in PCRE, provided that it was compiled with this sup-
       port  enabled.  This modifier also causes any non-printing characters in output strings to
       be printed using the \x{hh...} notation if they are valid UTF-8 sequences.

       If the /? modifier is used with /8, it causes pcretest to  call	pcre_compile()	with  the
       PCRE_NO_UTF8_CHECK option, to suppress the checking of the string for UTF-8 validity.


       Before  each  data  line  is  passed  to  pcre_exec(),  leading and trailing whitespace is
       removed, and it is then scanned for \ escapes. Some of these are pretty esoteric features,
       intended  for  checking out some of the more complicated features of PCRE. If you are just
       testing "ordinary" regular expressions, you probably don't need any of these. The  follow-
       ing escapes are recognized:

	 \a	    alarm (BEL, \x07)
	 \b	    backspace (\x08)
	 \e	    escape (\x27)
	 \f	    formfeed (\x0c)
	 \n	    newline (\x0a)
	 \qdd	    set the PCRE_MATCH_LIMIT limit to dd
		      (any number of digits)
	 \r	    carriage return (\x0d)
	 \t	    tab (\x09)
	 \v	    vertical tab (\x0b)
	 \nnn	    octal character (up to 3 octal digits)
	 \xhh	    hexadecimal character (up to 2 hex digits)
	 \x{hh...}  hexadecimal character, any number of digits
		      in UTF-8 mode
	 \A	    pass the PCRE_ANCHORED option to pcre_exec()
		      or pcre_dfa_exec()
	 \B	    pass the PCRE_NOTBOL option to pcre_exec()
		      or pcre_dfa_exec()
	 \Cdd	    call pcre_copy_substring() for substring dd
		      after a successful match (number less than 32)
	 \Cname     call pcre_copy_named_substring() for substring
		      "name" after a successful match (name termin-
		      ated by next non alphanumeric character)
	 \C+	    show the current captured substrings at callout
	 \C-	    do not supply a callout function
	 \C!n	    return 1 instead of 0 when callout number n is
	 \C!n!m     return 1 instead of 0 when callout number n is
		      reached for the nth time
	 \C*n	    pass the number n (may be negative) as callout
		      data; this is used as the callout return value
	 \D	    use the pcre_dfa_exec() match function
	 \F	    only shortest match for pcre_dfa_exec()
	 \Gdd	    call pcre_get_substring() for substring dd
		      after a successful match (number less than 32)
	 \Gname     call pcre_get_named_substring() for substring
		      "name" after a successful match (name termin-
		      ated by next non-alphanumeric character)
	 \L	    call pcre_get_substringlist() after a
		      successful match
	 \M	    discover the minimum MATCH_LIMIT and
		      MATCH_LIMIT_RECURSION settings
	 \N	    pass the PCRE_NOTEMPTY option to pcre_exec()
		      or pcre_dfa_exec()
	 \Odd	    set the size of the output vector passed to
		      pcre_exec() to dd (any number of digits)
	 \P	    pass the PCRE_PARTIAL option to pcre_exec()
		      or pcre_dfa_exec()
	 \Qdd	    set the PCRE_MATCH_LIMIT_RECURSION limit to dd
		      (any number of digits)
	 \R	    pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
	 \S	    output details of memory get/free calls during matching
	 \Z	    pass the PCRE_NOTEOL option to pcre_exec()
		      or pcre_dfa_exec()
	 \?	    pass the PCRE_NO_UTF8_CHECK option to
		      pcre_exec() or pcre_dfa_exec()
	 \>dd	    start the match at offset dd (any number of digits);
		      this sets the startoffset argument for pcre_exec()
		      or pcre_dfa_exec()
	 \<cr>	    pass the PCRE_NEWLINE_CR option to pcre_exec()
		      or pcre_dfa_exec()
	 \<lf>	    pass the PCRE_NEWLINE_LF option to pcre_exec()
		      or pcre_dfa_exec()
	 \<crlf>    pass the PCRE_NEWLINE_CRLF option to pcre_exec()
		      or pcre_dfa_exec()
	 \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre_exec()
		      or pcre_dfa_exec()
	 \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
		      or pcre_dfa_exec()

       The  escapes  that specify line ending sequences are literal strings, exactly as shown. No
       more than one newline setting should be present in any data line.

       A backslash followed by anything else just escapes the anything else.  If  the  very  last
       character  is  a  backslash,  it  is ignored. This gives a way of passing an empty line as
       data, since a real empty line terminates the data input.

       If \M is present, pcretest calls pcre_exec() several times, with different values  in  the
       match_limit  and  match_limit_recursion	fields of the pcre_extra data structure, until it
       finds the minimum numbers for each parameter  that  allow  pcre_exec()  to  complete.  The
       match_limit number is a measure of the amount of backtracking that takes place, and check-
       ing it out can be instructive. For most simple matches, the number is quite small, but for
       patterns  with  very  large  numbers  of  matching possibilities, it can become large very
       quickly with increasing length of subject string. The match_limit_recursion  number  is	a
       measure	of how much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory
       is needed to complete the match attempt.

       When \O is used, the value specified may be higher or lower than the size set  by  the  -O
       command	line  option (or defaulted to 45); \O applies only to the call of pcre_exec() for
       the line in which it appears.

       If the /P modifier was present on the pattern, causing the POSIX wrapper API to	be  used,
       the  only  option-setting sequences that have any effect are \B and \Z, causing REG_NOTBOL
       and REG_NOTEOL, respectively, to be passed to regexec().

       The use of \x{hh...} to represent UTF-8 characters is not dependent on the use of  the  /8
       modifier  on  the pattern. It is recognized always. There may be any number of hexadecimal
       digits inside the braces. The result is from one to six bytes, encoded  according  to  the
       original  UTF-8	rules  of  RFC 2279. This allows for values in the range 0 to 0x7FFFFFFF.
       Note that not all of those are valid Unicode code points, or indeed valid UTF-8 characters
       according to the later rules in RFC 3629.


       By  default,  pcretest uses the standard PCRE matching function, pcre_exec() to match each
       data  line.  From  release  6.0,  PCRE  supports   an   alternative   matching	function,
       pcre_dfa_test(), which operates in a different way, and has some restrictions. The differ-
       ences between the two functions are described in the pcrematching documentation.

       If a data line contains the \D escape sequence, or if the command line contains	the  -dfa
       option,	the  alternative  matching  function is called.  This function finds all possible
       matches at a given point. If, however, the \F escape sequence is present in the data line,
       it stops after the first match is found. This is always the shortest possible match.


       This section describes the output when the normal matching function, pcre_exec(), is being

       When a match succeeds, pcretest outputs the list of captured substrings	that  pcre_exec()
       returns,  starting with number 0 for the string that matched the whole pattern. Otherwise,
       it outputs "No match" or "Partial match" when pcre_exec()  returns  PCRE_ERROR_NOMATCH  or
       PCRE_ERROR_PARTIAL, respectively, and otherwise the PCRE negative error number. Here is an
       example of an interactive pcretest run.

	 $ pcretest
	 PCRE version 7.0 30-Nov-2006

	   re> /^abc(\d+)/
	 data> abc123
	  0: abc123
	  1: 123
	 data> xyz
	 No match

       Note that unset capturing substrings that are not followed by one  that	is  set  are  not
       returned  by  pcre_exec(),  and are not shown by pcretest. In the following example, there
       are two capturing substrings, but when the first data line is matched, the  second,  unset
       substring  is  not  shown. An "internal" unset substring is shown as "<unset>", as for the
       second data line.

	   re> /(a)|(b)/
	 data> a
	  0: a
	  1: a
	 data> b
	  0: b
	  1: <unset>
	  2: b

       If the strings contain any non-printing characters, they are output as \0x escapes, or  as
       \x{...}	escapes  if the /8 modifier was present on the pattern. See below for the defini-
       tion of non-printing characters. If the pattern has the /+ modifier, the output	for  sub-
       string 0 is followed by the the rest of the subject string, identified by "0+" like this:

	   re> /cat/+
	 data> cataract
	  0: cat
	  0+ aract

       If  the pattern has the /g or /G modifier, the results of successive matching attempts are
       output in sequence, like this:

	   re> /\Bi(\w\w)/g
	 data> Mississippi
	  0: iss
	  1: ss
	  0: iss
	  1: ss
	  0: ipp
	  1: pp

       "No match" is output only if the first match attempt fails.

       If any of the sequences \C, \G, or \L are present in a  data  line  that  is  successfully
       matched,  the substrings extracted by the convenience functions are output with C, G, or L
       after the string number instead of a colon. This is in addition to the normal  full  list.
       The string length (that is, the return from the extraction function) is given in parenthe-
       ses after each string for \C and \G.

       Note that whereas patterns can be continued over several lines (a plain ">" prompt is used
       for  continuations), data lines may not. However newlines can be included in data by means
       of the \n escape (or \r, \r\n, etc., depending on the newline sequence setting).


       When the alternative matching function, pcre_dfa_exec(), is  used  (by  means  of  the  \D
       escape sequence or the -dfa command line option), the output consists of a list of all the
       matches that start at the first point in the subject where there is at  least  one  match.
       For example:

	   re> /(tang|tangerine|tan)/
	 data> yellow tangerine\D
	  0: tangerine
	  1: tang
	  2: tan

       (Using  the normal matching function on this data finds only "tang".) The longest matching
       string is always given first (and numbered zero).

       If /g is present on the pattern, the search for further matches resumes at the end of  the
       longest match. For example:

	   re> /(tang|tangerine|tan)/g
	 data> yellow tangerine and tangy sultana\D
	  0: tangerine
	  1: tang
	  2: tan
	  0: tang
	  1: tan
	  0: tan

       Since  the matching function does not support substring capture, the escape sequences that
       are concerned with captured substrings are not relevant.


       When the alternative matching function has given the PCRE_ERROR_PARTIAL return, indicating
       that  the subject partially matched the pattern, you can restart the match with additional
       subject data by means of the \R escape sequence. For example:

	   re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
	 data> 23ja\P\D
	 Partial match: 23ja
	 data> n05\R\D
	  0: n05

       For further information about partial matching, see the pcrepartial documentation.


       If the pattern contains any callout requests, pcretest's callout function is called during
       matching.  This	works  with both matching functions. By default, the called function dis-
       plays the callout number, the start and current positions in the text at the callout time,
       and the next pattern item to be tested. For example, the output

	   0	^  ^	 \d

       indicates  that callout number 0 occurred for a match attempt starting at the fourth char-
       acter of the subject string, when the pointer was at the seventh character  of  the  data,
       and when the next pattern item was \d. Just one circumflex is output if the start and cur-
       rent positions are the same.

       Callouts numbered 255 are assumed to be automatic callouts, inserted as a result of the /C
       pattern	modifier.  In this case, instead of showing the callout number, the offset in the
       pattern, preceded by a plus, is output. For example:

	   re> /\d?[A-E]\*/C
	 data> E*
	  +0 ^	    \d?
	  +3 ^	    [A-E]
	  +8 ^^     \*
	 +10 ^ ^
	  0: E*

       The callout function in pcretest returns zero (carry on matching) by default, but you  can
       use a \C item in a data line (as described above) to change this.

       Inserting callouts can be helpful when using pcretest to check complicated regular expres-
       sions. For further information about callouts, see the pcrecallout documentation.


       When pcretest is outputting text in the compiled version of a pattern,  bytes  other  than
       32-126  are  always  treated  as  non-printing  characters  are are therefore shown as hex

       When pcretest is outputting text that is a matched part of a subject string, it behaves in
       the  same  way, unless a different locale has been set for the pattern (using the /L modi-
       fier). In this case, the isprint() function to distinguish printing and non-printing char-


       The facilities described in this section are not available when the POSIX inteface to PCRE
       is being used, that is, when the /P pattern modifier is specified.

       When the POSIX interface is not in use, you can cause pcretest to write a compiled pattern
       to a file, by following the modifiers with > and a file name.  For example:

	 /pattern/im >/some/file

       See  the  pcreprecompile documentation for a discussion about saving and re-using compiled

       The data that is written is binary. The first eight bytes are the length of  the  compiled
       pattern data followed by the length of the optional study data, each written as four bytes
       in big-endian order (most significant byte first). If there is no study data  (either  the
       pattern	was not studied, or studying did not return any data), the second length is zero.
       The lengths are followed by an exact copy of the compiled pattern. If there is  additional
       study  data,  this follows immediately after the compiled pattern. After writing the file,
       pcretest expects to read a new pattern.

       A saved pattern can be reloaded into pcretest by specifing < and a file name instead of	a
       pattern.  The  name of the file must not contain a < character, as otherwise pcretest will
       interpret the line as a pattern delimited by < characters.  For example:

	  re> </some/file
	 Compiled regex loaded from /some/file
	 No study data

       When the pattern has been loaded, pcretest proceeds to read data lines in the usual way.

       You can copy a file written by pcretest to a different host and reload it there,  even  if
       the  new  host  has  opposite endianness to the one on which the pattern was compiled. For
       example, you can compile on an i86 machine and run on a SPARC machine.

       File names for saving and reloading can be absolute or relative, but note that  the  shell
       facility of expanding a file name that starts with a tilde (~) is not available.

       The  ability to save and reload files in pcretest is intended for testing and experimenta-
       tion. It is not intended for production use because only a single pattern can  be  written
       to a file. Furthermore, there is no facility for supplying custom character tables for use
       with a reloaded pattern. If the original pattern  was  compiled	with  custom  tables,  an
       attempt	to match a subject string using a reloaded pattern is likely to cause pcretest to
       crash.  Finally, if you attempt to load a file that is not  in  the  correct  format,  the
       result is undefined.


       pcre(3),  pcreapi(3),  pcrecallout(3),  pcrematching(3),  pcrepartial(d),  pcrepattern(3),


       Philip Hazel
       University Computing Service
       Cambridge CB2 3QH, England.


       Last updated: 12 April 2008
       Copyright (c) 1997-2008 University of Cambridge.

       See attributes(5) for descriptions of the following attributes:

       |Availability	    | SUNWpcre	      |
       |Interface Stability | Uncommitted     |
       Source for PCRE is available on http://opensolaris.org.


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