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				2	<head>
				3	<title>pcretest specification</title>
				4	</head>
				5	<body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
				6	<h1>pcretest man page</h1>
				7	<p>
				8	Return to the <a href="index.html">PCRE index page</a>.
				9	</p>
				10	<p>
				11	This page is part of the PCRE HTML documentation. It was generated automatically
				12	from the original man page. If there is any nonsense in it, please consult the
				13	man page, in case the conversion went wrong.
				14	<br>
				15	<ul>
				16	<li><a name="TOC1" href="#SEC1">SYNOPSIS</a>
				17	<li><a name="TOC2" href="#SEC2">COMMAND LINE OPTIONS</a>
				18	<li><a name="TOC3" href="#SEC3">DESCRIPTION</a>
				19	<li><a name="TOC4" href="#SEC4">PATTERN MODIFIERS</a>
				20	<li><a name="TOC5" href="#SEC5">DATA LINES</a>
				21	<li><a name="TOC6" href="#SEC6">THE ALTERNATIVE MATCHING FUNCTION</a>
				22	<li><a name="TOC7" href="#SEC7">DEFAULT OUTPUT FROM PCRETEST</a>
				23	<li><a name="TOC8" href="#SEC8">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a>
				24	<li><a name="TOC9" href="#SEC9">RESTARTING AFTER A PARTIAL MATCH</a>
				25	<li><a name="TOC10" href="#SEC10">CALLOUTS</a>
				26	<li><a name="TOC11" href="#SEC11">NON-PRINTING CHARACTERS</a>
				27	<li><a name="TOC12" href="#SEC12">SAVING AND RELOADING COMPILED PATTERNS</a>
				28	<li><a name="TOC13" href="#SEC13">SEE ALSO</a>
				29	<li><a name="TOC14" href="#SEC14">AUTHOR</a>
				30	<li><a name="TOC15" href="#SEC15">REVISION</a>
				31	</ul>
				32	<br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
				33	<P>
				34	<b>pcretest [options] [input file [output file]]</b>
				35	<br>
				36	<br>
				37	<b>pcretest</b> was written as a test program for the PCRE regular expression
				38	library itself, but it can also be used for experimenting with regular
				39	expressions. This document describes the features of the test program; for
				40	details of the regular expressions themselves, see the
				41	<a href="pcrepattern.html"><b>pcrepattern</b></a>
				42	documentation. For details of the PCRE library function calls and their
				43	options, see the
				44	<a href="pcreapi.html"><b>pcreapi</b></a>
				45	documentation. The input for <b>pcretest</b> is a sequence of regular expression
				46	patterns and strings to be matched, as described below. The output shows the
				47	result of each match. Options on the command line and the patterns control PCRE
				48	options and exactly what is output.
				49	</P>
				50	<br><a name="SEC2" href="#TOC1">COMMAND LINE OPTIONS</a><br>
				51	<P>
				52	<b>-b</b>
				53	Behave as if each pattern has the <b>/B</b> (show byte code) modifier; the
				54	internal form is output after compilation.
				55	</P>
				56	<P>
				57	<b>-C</b>
				58	Output the version number of the PCRE library, and all available information
				59	about the optional features that are included, and then exit.
				60	</P>
				61	<P>
				62	<b>-d</b>
				63	Behave as if each pattern has the <b>/D</b> (debug) modifier; the internal
				64	form and information about the compiled pattern is output after compilation;
				65	<b>-d</b> is equivalent to <b>-b -i</b>.
				66	</P>
				67	<P>
				68	<b>-dfa</b>
				69	Behave as if each data line contains the \D escape sequence; this causes the
				70	alternative matching function, <b>pcre_dfa_exec()</b>, to be used instead of the
				71	standard <b>pcre_exec()</b> function (more detail is given below).
				72	</P>
				73	<P>
				74	<b>-help</b>
				75	Output a brief summary these options and then exit.
				76	</P>
				77	<P>
				78	<b>-i</b>
				79	Behave as if each pattern has the <b>/I</b> modifier; information about the
				80	compiled pattern is given after compilation.
				81	</P>
				82	<P>
				83	<b>-M</b>
				84	Behave as if each data line contains the \M escape sequence; this causes
				85	PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by
				86	calling <b>pcre_exec()</b> repeatedly with different limits.
				87	</P>
				88	<P>
				89	<b>-m</b>
				90	Output the size of each compiled pattern after it has been compiled. This is
				91	equivalent to adding <b>/M</b> to each regular expression.
				92	</P>
				93	<P>
				94	<b>-o</b> <i>osize</i>
				95	Set the number of elements in the output vector that is used when calling
				96	<b>pcre_exec()</b> or <b>pcre_dfa_exec()</b> to be <i>osize</i>. The default value
				97	is 45, which is enough for 14 capturing subexpressions for <b>pcre_exec()</b> or
				98	22 different matches for <b>pcre_dfa_exec()</b>. The vector size can be
				99	changed for individual matching calls by including \O in the data line (see
				100	below).
				101	</P>
				102	<P>
				103	<b>-p</b>
				104	Behave as if each pattern has the <b>/P</b> modifier; the POSIX wrapper API is
				105	used to call PCRE. None of the other options has any effect when <b>-p</b> is
				106	set.
				107	</P>
				108	<P>
				109	<b>-q</b>
				110	Do not output the version number of <b>pcretest</b> at the start of execution.
				111	</P>
				112	<P>
				113	<b>-S</b> <i>size</i>
				114	On Unix-like systems, set the size of the run-time stack to <i>size</i>
				115	megabytes.
				116	</P>
				117	<P>
				118	<b>-s</b> or <b>-s+</b>
				119	Behave as if each pattern has the <b>/S</b> modifier; in other words, force each
				120	pattern to be studied. If <b>-s+</b> is used, the PCRE_STUDY_JIT_COMPILE flag is
				121	passed to <b>pcre_study()</b>, causing just-in-time optimization to be set up if
				122	it is available. If the <b>/I</b> or <b>/D</b> option is present on a pattern
				123	(requesting output about the compiled pattern), information about the result of
				124	studying is not included when studying is caused only by <b>-s</b> and neither
				125	<b>-i</b> nor <b>-d</b> is present on the command line. This behaviour means that
				126	the output from tests that are run with and without <b>-s</b> should be
				127	identical, except when options that output information about the actual running
				128	of a match are set. The <b>-M</b>, <b>-t</b>, and <b>-tm</b> options, which give
				129	information about resources used, are likely to produce different output with
				130	and without <b>-s</b>. Output may also differ if the <b>/C</b> option is present
				131	on an individual pattern. This uses callouts to trace the the matching process,
				132	and this may be different between studied and non-studied patterns. If the
				133	pattern contains (*MARK) items there may also be differences, for the same
				134	reason. The <b>-s</b> command line option can be overridden for specific
				135	patterns that should never be studied (see the <b>/S</b> pattern modifier
				136	below).
				137	</P>
				138	<P>
				139	<b>-t</b>
				140	Run each compile, study, and match many times with a timer, and output
				141	resulting time per compile or match (in milliseconds). Do not set <b>-m</b> with
				142	<b>-t</b>, because you will then get the size output a zillion times, and the
				143	timing will be distorted. You can control the number of iterations that are
				144	used for timing by following <b>-t</b> with a number (as a separate item on the
				145	command line). For example, "-t 1000" would iterate 1000 times. The default is
				146	to iterate 500000 times.
				147	</P>
				148	<P>
				149	<b>-tm</b>
				150	This is like <b>-t</b> except that it times only the matching phase, not the
				151	compile or study phases.
				152	</P>
				153	<br><a name="SEC3" href="#TOC1">DESCRIPTION</a><br>
				154	<P>
				155	If <b>pcretest</b> is given two filename arguments, it reads from the first and
				156	writes to the second. If it is given only one filename argument, it reads from
				157	that file and writes to stdout. Otherwise, it reads from stdin and writes to
				158	stdout, and prompts for each line of input, using "re>" to prompt for regular
				159	expressions, and "data>" to prompt for data lines.
				160	</P>
				161	<P>
				162	When <b>pcretest</b> is built, a configuration option can specify that it should
				163	be linked with the <b>libreadline</b> library. When this is done, if the input
				164	is from a terminal, it is read using the <b>readline()</b> function. This
				165	provides line-editing and history facilities. The output from the <b>-help</b>
				166	option states whether or not <b>readline()</b> will be used.
				167	</P>
				168	<P>
				169	The program handles any number of sets of input on a single input file. Each
				170	set starts with a regular expression, and continues with any number of data
				171	lines to be matched against the pattern.
				172	</P>
				173	<P>
				174	Each data line is matched separately and independently. If you want to do
				175	multi-line matches, you have to use the \n escape sequence (or \r or \r\n,
				176	etc., depending on the newline setting) in a single line of input to encode the
				177	newline sequences. There is no limit on the length of data lines; the input
				178	buffer is automatically extended if it is too small.
				179	</P>
				180	<P>
				181	An empty line signals the end of the data lines, at which point a new regular
				182	expression is read. The regular expressions are given enclosed in any
				183	non-alphanumeric delimiters other than backslash, for example:
				184	<pre>
				185	/(a\|bc)x+yz/
				186	</pre>
				187	White space before the initial delimiter is ignored. A regular expression may
				188	be continued over several input lines, in which case the newline characters are
				189	included within it. It is possible to include the delimiter within the pattern
				190	by escaping it, for example
				191	<pre>
				192	/abc\/def/
				193	</pre>
				194	If you do so, the escape and the delimiter form part of the pattern, but since
				195	delimiters are always non-alphanumeric, this does not affect its interpretation.
				196	If the terminating delimiter is immediately followed by a backslash, for
				197	example,
				198	<pre>
				199	/abc/\
				200	</pre>
				201	then a backslash is added to the end of the pattern. This is done to provide a
				202	way of testing the error condition that arises if a pattern finishes with a
				203	backslash, because
				204	<pre>
				205	/abc\/
				206	</pre>
				207	is interpreted as the first line of a pattern that starts with "abc/", causing
				208	pcretest to read the next line as a continuation of the regular expression.
				209	</P>
				210	<br><a name="SEC4" href="#TOC1">PATTERN MODIFIERS</a><br>
				211	<P>
				212	A pattern may be followed by any number of modifiers, which are mostly single
				213	characters. Following Perl usage, these are referred to below as, for example,
				214	"the <b>/i</b> modifier", even though the delimiter of the pattern need not
				215	always be a slash, and no slash is used when writing modifiers. White space may
				216	appear between the final pattern delimiter and the first modifier, and between
				217	the modifiers themselves.
				218	</P>
				219	<P>
				220	The <b>/i</b>, <b>/m</b>, <b>/s</b>, and <b>/x</b> modifiers set the PCRE_CASELESS,
				221	PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when
				222	<b>pcre_compile()</b> is called. These four modifier letters have the same
				223	effect as they do in Perl. For example:
				224	<pre>
				225	/caseless/i
				226	</pre>
				227	The following table shows additional modifiers for setting PCRE compile-time
				228	options that do not correspond to anything in Perl:
				229	<pre>
				230	<b>/8</b> PCRE_UTF8
				231	<b>/?</b> PCRE_NO_UTF8_CHECK
				232	<b>/A</b> PCRE_ANCHORED
				233	<b>/C</b> PCRE_AUTO_CALLOUT
				234	<b>/E</b> PCRE_DOLLAR_ENDONLY
				235	<b>/f</b> PCRE_FIRSTLINE
				236	<b>/J</b> PCRE_DUPNAMES
				237	<b>/N</b> PCRE_NO_AUTO_CAPTURE
				238	<b>/U</b> PCRE_UNGREEDY
				239	<b>/W</b> PCRE_UCP
				240	<b>/X</b> PCRE_EXTRA
				241	<b>/Y</b> PCRE_NO_START_OPTIMIZE
				242	<b>/<JS></b> PCRE_JAVASCRIPT_COMPAT
				243	<b>/<cr></b> PCRE_NEWLINE_CR
				244	<b>/<lf></b> PCRE_NEWLINE_LF
				245	<b>/<crlf></b> PCRE_NEWLINE_CRLF
				246	<b>/<anycrlf></b> PCRE_NEWLINE_ANYCRLF
				247	<b>/<any></b> PCRE_NEWLINE_ANY
				248	<b>/<bsr_anycrlf></b> PCRE_BSR_ANYCRLF
				249	<b>/<bsr_unicode></b> PCRE_BSR_UNICODE
				250	</pre>
				251	The modifiers that are enclosed in angle brackets are literal strings as shown,
				252	including the angle brackets, but the letters within can be in either case.
				253	This example sets multiline matching with CRLF as the line ending sequence:
				254	<pre>
				255	/^abc/m<CRLF>
				256	</pre>
				257	As well as turning on the PCRE_UTF8 option, the <b>/8</b> modifier also causes
				258	any non-printing characters in output strings to be printed using the
				259	\x{hh...} notation if they are valid UTF-8 sequences. Full details of the PCRE
				260	options are given in the
				261	<a href="pcreapi.html"><b>pcreapi</b></a>
				262	documentation.
				263	</P>
				264	<br><b>
				265	Finding all matches in a string
				266	</b><br>
				267	<P>
				268	Searching for all possible matches within each subject string can be requested
				269	by the <b>/g</b> or <b>/G</b> modifier. After finding a match, PCRE is called
				270	again to search the remainder of the subject string. The difference between
				271	<b>/g</b> and <b>/G</b> is that the former uses the <i>startoffset</i> argument to
				272	<b>pcre_exec()</b> to start searching at a new point within the entire string
				273	(which is in effect what Perl does), whereas the latter passes over a shortened
				274	substring. This makes a difference to the matching process if the pattern
				275	begins with a lookbehind assertion (including \b or \B).
				276	</P>
				277	<P>
				278	If any call to <b>pcre_exec()</b> in a <b>/g</b> or <b>/G</b> sequence matches an
				279	empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
				280	PCRE_ANCHORED flags set in order to search for another, non-empty, match at the
				281	same point. If this second match fails, the start offset is advanced, and the
				282	normal match is retried. This imitates the way Perl handles such cases when
				283	using the <b>/g</b> modifier or the <b>split()</b> function. Normally, the start
				284	offset is advanced by one character, but if the newline convention recognizes
				285	CRLF as a newline, and the current character is CR followed by LF, an advance
				286	of two is used.
				287	</P>
				288	<br><b>
				289	Other modifiers
				290	</b><br>
				291	<P>
				292	There are yet more modifiers for controlling the way <b>pcretest</b>
				293	operates.
				294	</P>
				295	<P>
				296	The <b>/+</b> modifier requests that as well as outputting the substring that
				297	matched the entire pattern, <b>pcretest</b> should in addition output the
				298	remainder of the subject string. This is useful for tests where the subject
				299	contains multiple copies of the same substring. If the <b>+</b> modifier appears
				300	twice, the same action is taken for captured substrings. In each case the
				301	remainder is output on the following line with a plus character following the
				302	capture number. Note that this modifier must not immediately follow the /S
				303	modifier because /S+ has another meaning.
				304	</P>
				305	<P>
				306	The <b>/=</b> modifier requests that the values of all potential captured
				307	parentheses be output after a match by <b>pcre_exec()</b>. By default, only
				308	those up to the highest one actually used in the match are output
				309	(corresponding to the return code from <b>pcre_exec()</b>). Values in the
				310	offsets vector corresponding to higher numbers should be set to -1, and these
				311	are output as "<unset>". This modifier gives a way of checking that this is
				312	happening.
				313	</P>
				314	<P>
				315	The <b>/B</b> modifier is a debugging feature. It requests that <b>pcretest</b>
				316	output a representation of the compiled byte code after compilation. Normally
				317	this information contains length and offset values; however, if <b>/Z</b> is
				318	also present, this data is replaced by spaces. This is a special feature for
				319	use in the automatic test scripts; it ensures that the same output is generated
				320	for different internal link sizes.
				321	</P>
				322	<P>
				323	The <b>/D</b> modifier is a PCRE debugging feature, and is equivalent to
				324	<b>/BI</b>, that is, both the <b>/B</b> and the <b>/I</b> modifiers.
				325	</P>
				326	<P>
				327	The <b>/F</b> modifier causes <b>pcretest</b> to flip the byte order of the
				328	fields in the compiled pattern that contain 2-byte and 4-byte numbers. This
				329	facility is for testing the feature in PCRE that allows it to execute patterns
				330	that were compiled on a host with a different endianness. This feature is not
				331	available when the POSIX interface to PCRE is being used, that is, when the
				332	<b>/P</b> pattern modifier is specified. See also the section about saving and
				333	reloading compiled patterns below.
				334	</P>
				335	<P>
				336	The <b>/I</b> modifier requests that <b>pcretest</b> output information about the
				337	compiled pattern (whether it is anchored, has a fixed first character, and
				338	so on). It does this by calling <b>pcre_fullinfo()</b> after compiling a
				339	pattern. If the pattern is studied, the results of that are also output.
				340	</P>
				341	<P>
				342	The <b>/K</b> modifier requests <b>pcretest</b> to show names from backtracking
				343	control verbs that are returned from calls to <b>pcre_exec()</b>. It causes
				344	<b>pcretest</b> to create a <b>pcre_extra</b> block if one has not already been
				345	created by a call to <b>pcre_study()</b>, and to set the PCRE_EXTRA_MARK flag
				346	and the <b>mark</b> field within it, every time that <b>pcre_exec()</b> is
				347	called. If the variable that the <b>mark</b> field points to is non-NULL for a
				348	match, non-match, or partial match, <b>pcretest</b> prints the string to which
				349	it points. For a match, this is shown on a line by itself, tagged with "MK:".
				350	For a non-match it is added to the message.
				351	</P>
				352	<P>
				353	The <b>/L</b> modifier must be followed directly by the name of a locale, for
				354	example,
				355	<pre>
				356	/pattern/Lfr_FR
				357	</pre>
				358	For this reason, it must be the last modifier. The given locale is set,
				359	<b>pcre_maketables()</b> is called to build a set of character tables for the
				360	locale, and this is then passed to <b>pcre_compile()</b> when compiling the
				361	regular expression. Without an <b>/L</b> (or <b>/T</b>) modifier, NULL is passed
				362	as the tables pointer; that is, <b>/L</b> applies only to the expression on
				363	which it appears.
				364	</P>
				365	<P>
				366	The <b>/M</b> modifier causes the size of memory block used to hold the compiled
				367	pattern to be output. This does not include the size of the <b>pcre</b> block;
				368	it is just the actual compiled data. If the pattern is successfully studied
				369	with the PCRE_STUDY_JIT_COMPILE option, the size of the JIT compiled code is
				370	also output.
				371	</P>
				372	<P>
				373	If the <b>/S</b> modifier appears once, it causes <b>pcre_study()</b> to be
				374	called after the expression has been compiled, and the results used when the
				375	expression is matched. If <b>/S</b> appears twice, it suppresses studying, even
				376	if it was requested externally by the <b>-s</b> command line option. This makes
				377	it possible to specify that certain patterns are always studied, and others are
				378	never studied, independently of <b>-s</b>. This feature is used in the test
				379	files in a few cases where the output is different when the pattern is studied.
				380	</P>
				381	<P>
				382	If the <b>/S</b> modifier is immediately followed by a + character, the call to
				383	<b>pcre_study()</b> is made with the PCRE_STUDY_JIT_COMPILE option, requesting
				384	just-in-time optimization support if it is available. Note that there is also a
				385	<b>/+</b> modifier; it must not be given immediately after <b>/S</b> because this
				386	will be misinterpreted. If JIT studying is successful, it will automatically be
				387	used when <b>pcre_exec()</b> is run, except when incompatible run-time options
				388	are specified. These include the partial matching options; a complete list is
				389	given in the
				390	<a href="pcrejit.html"><b>pcrejit</b></a>
				391	documentation. See also the <b>\J</b> escape sequence below for a way of
				392	setting the size of the JIT stack.
				393	</P>
				394	<P>
				395	The <b>/T</b> modifier must be followed by a single digit. It causes a specific
				396	set of built-in character tables to be passed to <b>pcre_compile()</b>. It is
				397	used in the standard PCRE tests to check behaviour with different character
				398	tables. The digit specifies the tables as follows:
				399	<pre>
				400	0 the default ASCII tables, as distributed in
				401	pcre_chartables.c.dist
				402	1 a set of tables defining ISO 8859 characters
				403	</pre>
				404	In table 1, some characters whose codes are greater than 128 are identified as
				405	letters, digits, spaces, etc.
				406	</P>
				407	<br><b>
				408	Using the POSIX wrapper API
				409	</b><br>
				410	<P>
				411	The <b>/P</b> modifier causes <b>pcretest</b> to call PCRE via the POSIX wrapper
				412	API rather than its native API. When <b>/P</b> is set, the following modifiers
				413	set options for the <b>regcomp()</b> function:
				414	<pre>
				415	/i REG_ICASE
				416	/m REG_NEWLINE
				417	/N REG_NOSUB
				418	/s REG_DOTALL )
				419	/U REG_UNGREEDY ) These options are not part of
				420	/W REG_UCP ) the POSIX standard
				421	/8 REG_UTF8 )
				422	</pre>
				423	The <b>/+</b> modifier works as described above. All other modifiers are
				424	ignored.
				425	</P>
				426	<br><a name="SEC5" href="#TOC1">DATA LINES</a><br>
				427	<P>
				428	Before each data line is passed to <b>pcre_exec()</b>, leading and trailing
				429	white space is removed, and it is then scanned for \ escapes. Some of these
				430	are pretty esoteric features, intended for checking out some of the more
				431	complicated features of PCRE. If you are just testing "ordinary" regular
				432	expressions, you probably don't need any of these. The following escapes are
				433	recognized:
				434	<pre>
				435	\a alarm (BEL, \x07)
				436	\b backspace (\x08)
				437	\e escape (\x27)
				438	\f form feed (\x0c)
				439	\n newline (\x0a)
				440	\qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits)
				441	\r carriage return (\x0d)
				442	\t tab (\x09)
				443	\v vertical tab (\x0b)
				444	\nnn octal character (up to 3 octal digits)
				445	always a byte unless > 255 in UTF-8 mode
				446	\xhh hexadecimal byte (up to 2 hex digits)
				447	\x{hh...} hexadecimal character, any number of digits in UTF-8 mode
				448	\A pass the PCRE_ANCHORED option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				449	\B pass the PCRE_NOTBOL option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				450	\Cdd call pcre_copy_substring() for substring dd after a successful match (number less than 32)
				451	\Cname call pcre_copy_named_substring() for substring "name" after a successful match (name termin-
				452	ated by next non alphanumeric character)
				453	\C+ show the current captured substrings at callout time
				454	\C- do not supply a callout function
				455	\C!n return 1 instead of 0 when callout number n is reached
				456	\C!n!m return 1 instead of 0 when callout number n is reached for the nth time
				457	\C*n pass the number n (may be negative) as callout data; this is used as the callout return value
				458	\D use the <b>pcre_dfa_exec()</b> match function
				459	\F only shortest match for <b>pcre_dfa_exec()</b>
				460	\Gdd call pcre_get_substring() for substring dd after a successful match (number less than 32)
				461	\Gname call pcre_get_named_substring() for substring "name" after a successful match (name termin-
				462	ated by next non-alphanumeric character)
				463	\Jdd set up a JIT stack of dd kilobytes maximum (any number of digits)
				464	\L call pcre_get_substringlist() after a successful match
				465	\M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings
				466	\N pass the PCRE_NOTEMPTY option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>; if used twice, pass the
				467	PCRE_NOTEMPTY_ATSTART option
				468	\Odd set the size of the output vector passed to <b>pcre_exec()</b> to dd (any number of digits)
				469	\P pass the PCRE_PARTIAL_SOFT option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>; if used twice, pass the
				470	PCRE_PARTIAL_HARD option
				471	\Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits)
				472	\R pass the PCRE_DFA_RESTART option to <b>pcre_dfa_exec()</b>
				473	\S output details of memory get/free calls during matching
				474	\Y pass the PCRE_NO_START_OPTIMIZE option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				475	\Z pass the PCRE_NOTEOL option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				476	\? pass the PCRE_NO_UTF8_CHECK option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				477	\>dd start the match at offset dd (optional "-"; then any number of digits); this sets the <i>startoffset</i>
				478	argument for <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				479	\<cr> pass the PCRE_NEWLINE_CR option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				480	\<lf> pass the PCRE_NEWLINE_LF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				481	\<crlf> pass the PCRE_NEWLINE_CRLF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				482	\<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				483	\<any> pass the PCRE_NEWLINE_ANY option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>
				484	</pre>
				485	Note that \xhh always specifies one byte, even in UTF-8 mode; this makes it
				486	possible to construct invalid UTF-8 sequences for testing purposes. On the
				487	other hand, \x{hh} is interpreted as a UTF-8 character in UTF-8 mode,
				488	generating more than one byte if the value is greater than 127. When not in
				489	UTF-8 mode, it generates one byte for values less than 256, and causes an error
				490	for greater values.
				491	</P>
				492	<P>
				493	The escapes that specify line ending sequences are literal strings, exactly as
				494	shown. No more than one newline setting should be present in any data line.
				495	</P>
				496	<P>
				497	A backslash followed by anything else just escapes the anything else. If
				498	the very last character is a backslash, it is ignored. This gives a way of
				499	passing an empty line as data, since a real empty line terminates the data
				500	input.
				501	</P>
				502	<P>
				503	The <b>\J</b> escape provides a way of setting the maximum stack size that is
				504	used by the just-in-time optimization code. It is ignored if JIT optimization
				505	is not being used. Providing a stack that is larger than the default 32K is
				506	necessary only for very complicated patterns.
				507	</P>
				508	<P>
				509	If \M is present, <b>pcretest</b> calls <b>pcre_exec()</b> several times, with
				510	different values in the <i>match_limit</i> and <i>match_limit_recursion</i>
				511	fields of the <b>pcre_extra</b> data structure, until it finds the minimum
				512	numbers for each parameter that allow <b>pcre_exec()</b> to complete without
				513	error. Because this is testing a specific feature of the normal interpretive
				514	<b>pcre_exec()</b> execution, the use of any JIT optimization that might have
				515	been set up by the <b>/S+</b> qualifier of <b>-s+</b> option is disabled.
				516	</P>
				517	<P>
				518	The <i>match_limit</i> number is a measure of the amount of backtracking
				519	that takes place, and checking it out can be instructive. For most simple
				520	matches, the number is quite small, but for patterns with very large numbers of
				521	matching possibilities, it can become large very quickly with increasing length
				522	of subject string. The <i>match_limit_recursion</i> number is a measure of how
				523	much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is
				524	needed to complete the match attempt.
				525	</P>
				526	<P>
				527	When \O is used, the value specified may be higher or lower than the size set
				528	by the <b>-O</b> command line option (or defaulted to 45); \O applies only to
				529	the call of <b>pcre_exec()</b> for the line in which it appears.
				530	</P>
				531	<P>
				532	If the <b>/P</b> modifier was present on the pattern, causing the POSIX wrapper
				533	API to be used, the only option-setting sequences that have any effect are \B,
				534	\N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively,
				535	to be passed to <b>regexec()</b>.
				536	</P>
				537	<P>
				538	The use of \x{hh...} to represent UTF-8 characters is not dependent on the use
				539	of the <b>/8</b> modifier on the pattern. It is recognized always. There may be
				540	any number of hexadecimal digits inside the braces. The result is from one to
				541	six bytes, encoded according to the original UTF-8 rules of RFC 2279. This
				542	allows for values in the range 0 to 0x7FFFFFFF. Note that not all of those are
				543	valid Unicode code points, or indeed valid UTF-8 characters according to the
				544	later rules in RFC 3629.
				545	</P>
				546	<br><a name="SEC6" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
				547	<P>
				548	By default, <b>pcretest</b> uses the standard PCRE matching function,
				549	<b>pcre_exec()</b> to match each data line. From release 6.0, PCRE supports an
				550	alternative matching function, <b>pcre_dfa_test()</b>, which operates in a
				551	different way, and has some restrictions. The differences between the two
				552	functions are described in the
				553	<a href="pcrematching.html"><b>pcrematching</b></a>
				554	documentation.
				555	</P>
				556	<P>
				557	If a data line contains the \D escape sequence, or if the command line
				558	contains the <b>-dfa</b> option, the alternative matching function is called.
				559	This function finds all possible matches at a given point. If, however, the \F
				560	escape sequence is present in the data line, it stops after the first match is
				561	found. This is always the shortest possible match.
				562	</P>
				563	<br><a name="SEC7" href="#TOC1">DEFAULT OUTPUT FROM PCRETEST</a><br>
				564	<P>
				565	This section describes the output when the normal matching function,
				566	<b>pcre_exec()</b>, is being used.
				567	</P>
				568	<P>
				569	When a match succeeds, <b>pcretest</b> outputs the list of captured substrings
				570	that <b>pcre_exec()</b> returns, starting with number 0 for the string that
				571	matched the whole pattern. Otherwise, it outputs "No match" when the return is
				572	PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching
				573	substring when <b>pcre_exec()</b> returns PCRE_ERROR_PARTIAL. (Note that this is
				574	the entire substring that was inspected during the partial match; it may
				575	include characters before the actual match start if a lookbehind assertion,
				576	\K, \b, or \B was involved.) For any other return, <b>pcretest</b> outputs
				577	the PCRE negative error number and a short descriptive phrase. If the error is
				578	a failed UTF-8 string check, the byte offset of the start of the failing
				579	character and the reason code are also output, provided that the size of the
				580	output vector is at least two. Here is an example of an interactive
				581	<b>pcretest</b> run.
				582	<pre>
				583	$ pcretest
				584	PCRE version 8.13 2011-04-30
				585
				586	re> /^abc(\d+)/
				587	data> abc123
				588	0: abc123
				589	1: 123
				590	data> xyz
				591	No match
				592	</pre>
				593	Unset capturing substrings that are not followed by one that is set are not
				594	returned by <b>pcre_exec()</b>, and are not shown by <b>pcretest</b>. In the
				595	following example, there are two capturing substrings, but when the first data
				596	line is matched, the second, unset substring is not shown. An "internal" unset
				597	substring is shown as "<unset>", as for the second data line.
				598	<pre>
				599	re> /(a)\|(b)/
				600	data> a
				601	0: a
				602	1: a
				603	data> b
				604	0: b
				605	1: <unset>
				606	2: b
				607	</pre>
				608	If the strings contain any non-printing characters, they are output as \0x
				609	escapes, or as \x{...} escapes if the <b>/8</b> modifier was present on the
				610	pattern. See below for the definition of non-printing characters. If the
				611	pattern has the <b>/+</b> modifier, the output for substring 0 is followed by
				612	the the rest of the subject string, identified by "0+" like this:
				613	<pre>
				614	re> /cat/+
				615	data> cataract
				616	0: cat
				617	0+ aract
				618	</pre>
				619	If the pattern has the <b>/g</b> or <b>/G</b> modifier, the results of successive
				620	matching attempts are output in sequence, like this:
				621	<pre>
				622	re> /\Bi(\w\w)/g
				623	data> Mississippi
				624	0: iss
				625	1: ss
				626	0: iss
				627	1: ss
				628	0: ipp
				629	1: pp
				630	</pre>
				631	"No match" is output only if the first match attempt fails. Here is an example
				632	of a failure message (the offset 4 that is specified by \>4 is past the end of
				633	the subject string):
				634	<pre>
				635	re> /xyz/
				636	data> xyz\>4
				637	Error -24 (bad offset value)
				638	</PRE>
				639	</P>
				640	<P>
				641	If any of the sequences <b>\C</b>, <b>\G</b>, or <b>\L</b> are present in a
				642	data line that is successfully matched, the substrings extracted by the
				643	convenience functions are output with C, G, or L after the string number
				644	instead of a colon. This is in addition to the normal full list. The string
				645	length (that is, the return from the extraction function) is given in
				646	parentheses after each string for <b>\C</b> and <b>\G</b>.
				647	</P>
				648	<P>
				649	Note that whereas patterns can be continued over several lines (a plain ">"
				650	prompt is used for continuations), data lines may not. However newlines can be
				651	included in data by means of the \n escape (or \r, \r\n, etc., depending on
				652	the newline sequence setting).
				653	</P>
				654	<br><a name="SEC8" href="#TOC1">OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION</a><br>
				655	<P>
				656	When the alternative matching function, <b>pcre_dfa_exec()</b>, is used (by
				657	means of the \D escape sequence or the <b>-dfa</b> command line option), the
				658	output consists of a list of all the matches that start at the first point in
				659	the subject where there is at least one match. For example:
				660	<pre>
				661	re> /(tang\|tangerine\|tan)/
				662	data> yellow tangerine\D
				663	0: tangerine
				664	1: tang
				665	2: tan
				666	</pre>
				667	(Using the normal matching function on this data finds only "tang".) The
				668	longest matching string is always given first (and numbered zero). After a
				669	PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the
				670	partially matching substring. (Note that this is the entire substring that was
				671	inspected during the partial match; it may include characters before the actual
				672	match start if a lookbehind assertion, \K, \b, or \B was involved.)
				673	</P>
				674	<P>
				675	If <b>/g</b> is present on the pattern, the search for further matches resumes
				676	at the end of the longest match. For example:
				677	<pre>
				678	re> /(tang\|tangerine\|tan)/g
				679	data> yellow tangerine and tangy sultana\D
				680	0: tangerine
				681	1: tang
				682	2: tan
				683	0: tang
				684	1: tan
				685	0: tan
				686	</pre>
				687	Since the matching function does not support substring capture, the escape
				688	sequences that are concerned with captured substrings are not relevant.
				689	</P>
				690	<br><a name="SEC9" href="#TOC1">RESTARTING AFTER A PARTIAL MATCH</a><br>
				691	<P>
				692	When the alternative matching function has given the PCRE_ERROR_PARTIAL return,
				693	indicating that the subject partially matched the pattern, you can restart the
				694	match with additional subject data by means of the \R escape sequence. For
				695	example:
				696	<pre>
				697	re> /^\d?\d(jan\|feb\|mar\|apr\|may\|jun\|jul\|aug\|sep\|oct\|nov\|dec)\d\d$/
				698	data> 23ja\P\D
				699	Partial match: 23ja
				700	data> n05\R\D
				701	0: n05
				702	</pre>
				703	For further information about partial matching, see the
				704	<a href="pcrepartial.html"><b>pcrepartial</b></a>
				705	documentation.
				706	</P>
				707	<br><a name="SEC10" href="#TOC1">CALLOUTS</a><br>
				708	<P>
				709	If the pattern contains any callout requests, <b>pcretest</b>'s callout function
				710	is called during matching. This works with both matching functions. By default,
				711	the called function displays the callout number, the start and current
				712	positions in the text at the callout time, and the next pattern item to be
				713	tested. For example, the output
				714	<pre>
				715	--->pqrabcdef
				716	0 ^ ^ \d
				717	</pre>
				718	indicates that callout number 0 occurred for a match attempt starting at the
				719	fourth character of the subject string, when the pointer was at the seventh
				720	character of the data, and when the next pattern item was \d. Just one
				721	circumflex is output if the start and current positions are the same.
				722	</P>
				723	<P>
				724	Callouts numbered 255 are assumed to be automatic callouts, inserted as a
				725	result of the <b>/C</b> pattern modifier. In this case, instead of showing the
				726	callout number, the offset in the pattern, preceded by a plus, is output. For
				727	example:
				728	<pre>
				729	re> /\d?[A-E]\*/C
				730	data> E*
				731	--->E*
				732	+0 ^ \d?
				733	+3 ^ [A-E]
				734	+8 ^^ \*
				735	+10 ^ ^
				736	0: E*
				737	</pre>
				738	If a pattern contains (*MARK) items, an additional line is output whenever
				739	a change of latest mark is passed to the callout function. For example:
				740	<pre>
				741	re> /a(*MARK:X)bc/C
				742	data> abc
				743	--->abc
				744	+0 ^ a
				745	+1 ^^ (*MARK:X)
				746	+10 ^^ b
				747	Latest Mark: X
				748	+11 ^ ^ c
				749	+12 ^ ^
				750	0: abc
				751	</pre>
				752	The mark changes between matching "a" and "b", but stays the same for the rest
				753	of the match, so nothing more is output. If, as a result of backtracking, the
				754	mark reverts to being unset, the text "<unset>" is output.
				755	</P>
				756	<P>
				757	The callout function in <b>pcretest</b> returns zero (carry on matching) by
				758	default, but you can use a \C item in a data line (as described above) to
				759	change this and other parameters of the callout.
				760	</P>
				761	<P>
				762	Inserting callouts can be helpful when using <b>pcretest</b> to check
				763	complicated regular expressions. For further information about callouts, see
				764	the
				765	<a href="pcrecallout.html"><b>pcrecallout</b></a>
				766	documentation.
				767	</P>
				768	<br><a name="SEC11" href="#TOC1">NON-PRINTING CHARACTERS</a><br>
				769	<P>
				770	When <b>pcretest</b> is outputting text in the compiled version of a pattern,
				771	bytes other than 32-126 are always treated as non-printing characters are are
				772	therefore shown as hex escapes.
				773	</P>
				774	<P>
				775	When <b>pcretest</b> is outputting text that is a matched part of a subject
				776	string, it behaves in the same way, unless a different locale has been set for
				777	the pattern (using the <b>/L</b> modifier). In this case, the <b>isprint()</b>
				778	function to distinguish printing and non-printing characters.
				779	</P>
				780	<br><a name="SEC12" href="#TOC1">SAVING AND RELOADING COMPILED PATTERNS</a><br>
				781	<P>
				782	The facilities described in this section are not available when the POSIX
				783	interface to PCRE is being used, that is, when the <b>/P</b> pattern modifier is
				784	specified.
				785	</P>
				786	<P>
				787	When the POSIX interface is not in use, you can cause <b>pcretest</b> to write a
				788	compiled pattern to a file, by following the modifiers with > and a file name.
				789	For example:
				790	<pre>
				791	/pattern/im >/some/file
				792	</pre>
				793	See the
				794	<a href="pcreprecompile.html"><b>pcreprecompile</b></a>
				795	documentation for a discussion about saving and re-using compiled patterns.
				796	Note that if the pattern was successfully studied with JIT optimization, the
				797	JIT data cannot be saved.
				798	</P>
				799	<P>
				800	The data that is written is binary. The first eight bytes are the length of the
				801	compiled pattern data followed by the length of the optional study data, each
				802	written as four bytes in big-endian order (most significant byte first). If
				803	there is no study data (either the pattern was not studied, or studying did not
				804	return any data), the second length is zero. The lengths are followed by an
				805	exact copy of the compiled pattern. If there is additional study data, this
				806	(excluding any JIT data) follows immediately after the compiled pattern. After
				807	writing the file, <b>pcretest</b> expects to read a new pattern.
				808	</P>
				809	<P>
				810	A saved pattern can be reloaded into <b>pcretest</b> by specifying < and a file
				811	name instead of a pattern. The name of the file must not contain a < character,
				812	as otherwise <b>pcretest</b> will interpret the line as a pattern delimited by <
				813	characters.
				814	For example:
				815	<pre>
				816	re> </some/file
				817	Compiled pattern loaded from /some/file
				818	No study data
				819	</pre>
				820	If the pattern was previously studied with the JIT optimization, the JIT
				821	information cannot be saved and restored, and so is lost. When the pattern has
				822	been loaded, <b>pcretest</b> proceeds to read data lines in the usual way.
				823	</P>
				824	<P>
				825	You can copy a file written by <b>pcretest</b> to a different host and reload it
				826	there, even if the new host has opposite endianness to the one on which the
				827	pattern was compiled. For example, you can compile on an i86 machine and run on
				828	a SPARC machine.
				829	</P>
				830	<P>
				831	File names for saving and reloading can be absolute or relative, but note that
				832	the shell facility of expanding a file name that starts with a tilde (~) is not
				833	available.
				834	</P>
				835	<P>
				836	The ability to save and reload files in <b>pcretest</b> is intended for testing
				837	and experimentation. It is not intended for production use because only a
				838	single pattern can be written to a file. Furthermore, there is no facility for
				839	supplying custom character tables for use with a reloaded pattern. If the
				840	original pattern was compiled with custom tables, an attempt to match a subject
				841	string using a reloaded pattern is likely to cause <b>pcretest</b> to crash.
				842	Finally, if you attempt to load a file that is not in the correct format, the
				843	result is undefined.
				844	</P>
				845	<br><a name="SEC13" href="#TOC1">SEE ALSO</a><br>
				846	<P>
				847	<b>pcre</b>(3), <b>pcreapi</b>(3), <b>pcrecallout</b>(3), <b>pcrejit</b>,
				848	<b>pcrematching</b>(3), <b>pcrepartial</b>(d), <b>pcrepattern</b>(3),
				849	<b>pcreprecompile</b>(3).
				850	</P>
				851	<br><a name="SEC14" href="#TOC1">AUTHOR</a><br>
				852	<P>
				853	Philip Hazel
				854	<br>
				855	University Computing Service
				856	<br>
				857	Cambridge CB2 3QH, England.
				858	<br>
				859	</P>
				860	<br><a name="SEC15" href="#TOC1">REVISION</a><br>
				861	<P>
				862	Last updated: 02 December 2011
				863	<br>
				864	Copyright © 1997-2011 University of Cambridge.
				865	<br>
				866	<p>
				867	Return to the <a href="index.html">PCRE index page</a>.
				868	</p>