+Return to the PCRE index page. +
+
+This page is part of the PCRE HTML documentation. It was generated automatically
+from the original man page. If there is any nonsense in it, please consult the
+man page, in case the conversion went wrong.
+
+
+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 equivalent 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 +standard 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 pattern 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 earlier 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 lines. +
++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 output 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 small. +
++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: +
+ /(a|bc)x+yz/ ++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 +
+ /abc\/def/ ++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, +
+ /abc/\ ++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 +
+ /abc\/ ++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: +
+ /caseless/i ++The following table shows additional modifiers for setting PCRE options that do +not correspond to anything in Perl: +
+ /A PCRE_ANCHORED + /C PCRE_AUTO_CALLOUT + /E PCRE_DOLLAR_ENDONLY + /f PCRE_FIRSTLINE + /J PCRE_DUPNAMES + /N PCRE_NO_AUTO_CAPTURE + /U PCRE_UNGREEDY + /X PCRE_EXTRA + /<JS> PCRE_JAVASCRIPT_COMPAT + /<cr> PCRE_NEWLINE_CR + /<lf> PCRE_NEWLINE_LF + /<crlf> PCRE_NEWLINE_CRLF + /<anycrlf> PCRE_NEWLINE_ANYCRLF + /<any> PCRE_NEWLINE_ANY + /<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 sequence: +
+ /^abc/m<crlf> ++Details of the meanings of these PCRE options are given in the +pcreapi +documentation. + +
+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 assertion (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. +
++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, +
+ /pattern/Lfr_FR ++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 appears. + +
+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 pattern 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 output. +
++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 support 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 following 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 time
+ \C- do not supply a callout function
+ \C!n return 1 instead of 0 when callout number n is reached
+ \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 checking 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 differences 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 used. +
++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 definition of non-printing characters. If the +pattern has the /+ modifier, the output for substring 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 +parentheses 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 displays 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 +
+ --->pqrabcdef + 0 ^ ^ \d ++indicates that callout number 0 occurred for a match attempt starting at the +fourth character 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 current 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* + --->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 expressions. 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 escapes. +
++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 modifier). In this case, the isprint() +function to distinguish printing and non-printing characters. +
++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 patterns. + +
+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 experimentation. 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), pcreprecompile(3). +
+
+Philip Hazel
+
+University Computing Service
+
+Cambridge CB2 3QH, England.
+
+
+Last updated: 12 April 2008
+
+Copyright © 1997-2008 University of Cambridge.
+
+
+Return to the PCRE index page. +