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    1 PCRETEST(1)                 General Commands Manual                PCRETEST(1)
    2 
    3 
    4 
    5 NAME
    6        pcretest - a program for testing Perl-compatible regular expressions.
    7 
    8 SYNOPSIS
    9 
   10        pcretest [options] [input file [output file]]
   11 
   12        pcretest  was written as a test program for the PCRE regular expression
   13        library itself, but it can also be used for experimenting with  regular
   14        expressions.  This document describes the features of the test program;
   15        for details of the regular expressions themselves, see the  pcrepattern
   16        documentation. For details of the PCRE library function calls and their
   17        options, see the pcreapi , pcre16 and pcre32 documentation.
   18 
   19        The input for pcretest is a sequence of regular expression patterns and
   20        strings  to be matched, as described below. The output shows the result
   21        of each match. Options on the command line  and  the  patterns  control
   22        PCRE options and exactly what is output.
   23 
   24        As  PCRE has evolved, it has acquired many different features, and as a
   25        result, pcretest now has rather a lot of obscure  options  for  testing
   26        every possible feature. Some of these options are specifically designed
   27        for use in conjunction with the test script and  data  files  that  are
   28        distributed  as  part of PCRE, and are unlikely to be of use otherwise.
   29        They are all documented here, but without much justification.
   30 
   31 
   32 INPUT DATA FORMAT
   33 
   34        Input to pcretest is processed line by line, either by  calling  the  C
   35        library's fgets() function, or via the libreadline library (see below).
   36        In Unix-like environments, fgets() treats any bytes other than  newline
   37        as  data characters. However, in some Windows environments character 26
   38        (hex 1A) causes an immediate end of file, and no further data is  read.
   39        For  maximum  portability,  therefore,  it  is safest to use only ASCII
   40        characters in pcretest input files.
   41 
   42        The input is processed using using C's string functions,  so  must  not
   43        contain  binary  zeroes, even though in Unix-like environments, fgets()
   44        treats any bytes other than newline as data characters.
   45 
   46 
   47 PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES
   48 
   49        From release 8.30, two separate PCRE libraries can be built. The origi-
   50        nal  one supports 8-bit character strings, whereas the newer 16-bit li-
   51        brary supports character strings encoded in 16-bit units. From  release
   52        8.32,  a  third  library can be built, supporting character strings en-
   53        coded in 32-bit units. The pcretest program can be  used  to  test  all
   54        three  libraries. However, it is itself still an 8-bit program, reading
   55        8-bit input and writing 8-bit  output.   When  testing  the  16-bit  or
   56        32-bit  library,  the patterns and data strings are converted to 16- or
   57        32-bit format before being passed to the PCRE  library  functions.  Re-
   58        sults are converted to 8-bit for output.
   59 
   60        References to functions and structures of the form pcre[16|32]_xx below
   61        mean "pcre_xx when using the 8-bit library, pcre16_xx  when  using  the
   62        16-bit library, or pcre32_xx when using the 32-bit library".
   63 
   64 
   65 COMMAND LINE OPTIONS
   66 
   67        -8        If the 8-bit library has been built, this option causes it to
   68                  be used (this is the default). If the 8-bit library  has  not
   69                  been built, this option causes an error.
   70 
   71        -16       If  the  16-bit library has been built, this option causes it
   72                  to be used. If only the 16-bit library has been  built,  this
   73                  is  the  default.  If  the 16-bit library has not been built,
   74                  this option causes an error.
   75 
   76        -32       If the 32-bit library has been built, this option  causes  it
   77                  to  be  used. If only the 32-bit library has been built, this
   78                  is the default. If the 32-bit library  has  not  been  built,
   79                  this option causes an error.
   80 
   81        -b        Behave  as  if each pattern has the /B (show byte code) modi-
   82                  fier; the internal form is output after compilation.
   83 
   84        -C        Output the version number of the PCRE library, and all avail-
   85                  able  information  about  the  optional features that are in-
   86                  cluded, and then exit with zero exit code. All other  options
   87                  are ignored.
   88 
   89        -C option Output  information  about a specific build-time option, then
   90                  exit. This functionality is intended for use in scripts  such
   91                  as  RunTest.  The  following options output the value and set
   92                  the exit code as indicated:
   93 
   94                    ebcdic-nl  the code for LF (= NL) in an EBCDIC environment:
   95                                 0x15 or 0x25
   96                                 0 if used in an ASCII environment
   97                                 exit code is always 0
   98                    linksize   the configured internal link size (2, 3, or 4)
   99                                 exit code is set to the link size
  100                    newline    the default newline setting:
  101                                 CR, LF, CRLF, ANYCRLF, or ANY
  102                                 exit code is always 0
  103                    bsr        the default setting for what \R matches:
  104                                 ANYCRLF or ANY
  105                                 exit code is always 0
  106 
  107                  The following options output 1 for true or 0 for  false,  and
  108                  set the exit code to the same value:
  109 
  110                    ebcdic     compiled for an EBCDIC environment
  111                    jit        just-in-time support is available
  112                    pcre16     the 16-bit library was built
  113                    pcre32     the 32-bit library was built
  114                    pcre8      the 8-bit library was built
  115                    ucp        Unicode property support is available
  116                    utf        UTF-8 and/or UTF-16 and/or UTF-32 support
  117                                 is available
  118 
  119                  If  an  unknown  option is given, an error message is output;
  120                  the exit code is 0.
  121 
  122        -d        Behave as if each pattern has the /D  (debug)  modifier;  the
  123                  internal  form  and information about the compiled pattern is
  124                  output after compilation; -d is equivalent to -b -i.
  125 
  126        -dfa      Behave as if each data line contains the \D escape  sequence;
  127                  this    causes    the    alternative    matching    function,
  128                  pcre[16|32]_dfa_exec(), to be used instead  of  the  standard
  129                  pcre[16|32]_exec() function (more detail is given below).
  130 
  131        -help     Output a brief summary these options and then exit.
  132 
  133        -i        Behave  as  if  each pattern has the /I modifier; information
  134                  about the compiled pattern is given after compilation.
  135 
  136        -M        Behave as if each data line contains the \M escape  sequence;
  137                  this  causes  PCRE  to  discover  the minimum MATCH_LIMIT and
  138                  MATCH_LIMIT_RECURSION settings by calling  pcre[16|32]_exec()
  139                  repeatedly with different limits.
  140 
  141        -m        Output  the  size  of each compiled pattern after it has been
  142                  compiled. This is equivalent to adding /M to each regular ex-
  143                  pression. The size is given in bytes for both libraries.
  144 
  145        -O        Behave  as  if each pattern has the /O modifier, that is dis-
  146                  able auto-possessification for all patterns.
  147 
  148        -o osize  Set the number of elements in the output vector that is  used
  149                  when  calling pcre[16|32]_exec() or pcre[16|32]_dfa_exec() to
  150                  be osize. The default value is 45, which  is  enough  for  14
  151                  capturing subexpressions for pcre[16|32]_exec() or 22 differ-
  152                  ent matches for pcre[16|32]_dfa_exec().  The vector size  can
  153                  be  changed  for individual matching calls by including \O in
  154                  the data line (see below).
  155 
  156        -p        Behave as if each pattern has  the  /P  modifier;  the  POSIX
  157                  wrapper  API  is used to call PCRE. None of the other options
  158                  has any effect when -p is set. This option can be  used  only
  159                  with the 8-bit library.
  160 
  161        -q        Do  not output the version number of pcretest at the start of
  162                  execution.
  163 
  164        -S size   On Unix-like systems, set the size of the run-time  stack  to
  165                  size megabytes.
  166 
  167        -s or -s+ Behave  as  if  each  pattern  has  the /S modifier; in other
  168                  words, force each pattern to be studied. If -s+ is used,  all
  169                  the  JIT  compile  options are passed to pcre[16|32]_study(),
  170                  causing just-in-time optimization to  be  set  up  if  it  is
  171                  available,  for  both full and partial matching. Specific JIT
  172                  compile options can be selected by following -s+ with a digit
  173                  in  the  range 1 to 7, which selects the JIT compile modes as
  174                  follows:
  175 
  176                    1  normal match only
  177                    2  soft partial match only
  178                    3  normal match and soft partial match
  179                    4  hard partial match only
  180                    6  soft and hard partial match
  181                    7  all three modes (default)
  182 
  183                  If -s++ is used instead of -s+ (with or without  a  following
  184                  digit),  the  text  "(JIT)" is added to the first output line
  185                  after a match or no match when JIT-compiled code was actually
  186                  used.
  187 
  188                  Note that there are pattern options that can override -s, ei-
  189                  ther specifying no studying at all, or suppressing JIT compi-
  190                  lation.
  191 
  192                  If  the  /I  or /D option is present on a pattern (requesting
  193                  output about the compiled pattern), information about the re-
  194                  sult of studying is not included when studying is caused only
  195                  by -s and neither -i nor -d is present on the  command  line.
  196                  This  behaviour means that the output from tests that are run
  197                  with and without -s should be identical, except when  options
  198                  that  output  information about the actual running of a match
  199                  are set.
  200 
  201                  The -M, -t, and -tm options, which give information about re-
  202                  sources used, are likely to produce different output with and
  203                  without -s. Output may  also  differ  if  the  /C  option  is
  204                  present on an individual pattern. This uses callouts to trace
  205                  the the matching process, and this may be  different  between
  206                  studied  and  non-studied  patterns.  If the pattern contains
  207                  (*MARK) items there may also be  differences,  for  the  same
  208                  reason. The -s command line option can be overridden for spe-
  209                  cific patterns that should never be studied (see the /S  pat-
  210                  tern modifier below).
  211 
  212        -t        Run  each  compile, study, and match many times with a timer,
  213                  and output the resulting times per compile, study,  or  match
  214                  (in  milliseconds).  Do  not set -m with -t, because you will
  215                  then get the size output a zillion times, and the timing will
  216                  be  distorted.  You can control the number of iterations that
  217                  are used for timing by following -t with a number (as a sepa-
  218                  rate  item on the command line). For example, "-t 1000" iter-
  219                  ates 1000 times.  The default is to iterate 500000 times.
  220 
  221        -tm       This is like -t except that it times only the matching phase,
  222                  not the compile or study phases.
  223 
  224        -T -TM    These  behave like -t and -tm, but in addition, at the end of
  225                  a run, the total times for all compiles, studies, and matches
  226                  are output.
  227 
  228 
  229 DESCRIPTION
  230 
  231        If  pcretest  is  given two filename arguments, it reads from the first
  232        and writes to the second. If it is given only one filename argument, it
  233        reads  from  that  file  and writes to stdout. Otherwise, it reads from
  234        stdin and writes to stdout, and prompts for each line of  input,  using
  235        "re>" to prompt for regular expressions, and "data>" to prompt for data
  236        lines.
  237 
  238        When pcretest is built, a configuration  option  can  specify  that  it
  239        should  be  linked  with the libreadline library. When this is done, if
  240        the input is from a terminal, it is read using the readline() function.
  241        This  provides line-editing and history facilities. The output from the
  242        -help option states whether or not readline() will be used.
  243 
  244        The program handles any number of sets of input on a single input file.
  245        Each  set starts with a regular expression, and continues with any num-
  246        ber of data lines to be matched against that pattern.
  247 
  248        Each data line is matched separately and independently. If you want  to
  249        do multi-line matches, you have to use the \n escape sequence (or \r or
  250        \r\n, etc., depending on the newline setting) in a single line of input
  251        to  encode  the  newline  sequences. There is no limit on the length of
  252        data lines; the input buffer is automatically extended  if  it  is  too
  253        small.
  254 
  255        An  empty  line signals the end of the data lines, at which point a new
  256        regular expression is read. The regular expressions are given  enclosed
  257        in any non-alphanumeric delimiters other than backslash, for example:
  258 
  259          /(a|bc)x+yz/
  260 
  261        White  space before the initial delimiter is ignored. A regular expres-
  262        sion may be continued over several input lines, in which case the  new-
  263        line  characters  are included within it. It is possible to include the
  264        delimiter within the pattern by escaping it, for example
  265 
  266          /abc\/def/
  267 
  268        If you do so, the escape and the delimiter form part  of  the  pattern,
  269        but  since delimiters are always non-alphanumeric, this does not affect
  270        its interpretation.  If the terminating delimiter is  immediately  fol-
  271        lowed by a backslash, for example,
  272 
  273          /abc/\
  274 
  275        then  a  backslash  is added to the end of the pattern. This is done to
  276        provide a way of testing the error condition that arises if  a  pattern
  277        finishes with a backslash, because
  278 
  279          /abc\/
  280 
  281        is  interpreted as the first line of a pattern that starts with "abc/",
  282        causing pcretest to read the next line as a continuation of the regular
  283        expression.
  284 
  285 
  286 PATTERN MODIFIERS
  287 
  288        A  pattern may be followed by any number of modifiers, which are mostly
  289        single characters, though some of these can  be  qualified  by  further
  290        characters.   Following Perl usage, these are referred to below as, for
  291        example, "the /i modifier", even though the delimiter  of  the  pattern
  292        need  not  always  be  a slash, and no slash is used when writing modi-
  293        fiers. White space may appear between the final pattern  delimiter  and
  294        the  first  modifier,  and between the modifiers themselves. For refer-
  295        ence, here is a complete list of  modifiers.  They  fall  into  several
  296        groups that are described in detail in the following sections.
  297 
  298          /8              set UTF mode
  299          /9              set PCRE_NEVER_UTF (locks out UTF mode)
  300          /?              disable UTF validity check
  301          /+              show remainder of subject after match
  302          /=              show all captures (not just those that are set)
  303 
  304          /A              set PCRE_ANCHORED
  305          /B              show compiled code
  306          /C              set PCRE_AUTO_CALLOUT
  307          /D              same as /B plus /I
  308          /E              set PCRE_DOLLAR_ENDONLY
  309          /F              flip byte order in compiled pattern
  310          /f              set PCRE_FIRSTLINE
  311          /G              find all matches (shorten string)
  312          /g              find all matches (use startoffset)
  313          /I              show information about pattern
  314          /i              set PCRE_CASELESS
  315          /J              set PCRE_DUPNAMES
  316          /K              show backtracking control names
  317          /L              set locale
  318          /M              show compiled memory size
  319          /m              set PCRE_MULTILINE
  320          /N              set PCRE_NO_AUTO_CAPTURE
  321          /O              set PCRE_NO_AUTO_POSSESS
  322          /P              use the POSIX wrapper
  323          /Q              test external stack check function
  324          /S              study the pattern after compilation
  325          /s              set PCRE_DOTALL
  326          /T              select character tables
  327          /U              set PCRE_UNGREEDY
  328          /W              set PCRE_UCP
  329          /X              set PCRE_EXTRA
  330          /x              set PCRE_EXTENDED
  331          /Y              set PCRE_NO_START_OPTIMIZE
  332          /Z              don't show lengths in /B output
  333 
  334          /<any>          set PCRE_NEWLINE_ANY
  335          /<anycrlf>      set PCRE_NEWLINE_ANYCRLF
  336          /<cr>           set PCRE_NEWLINE_CR
  337          /<crlf>         set PCRE_NEWLINE_CRLF
  338          /<lf>           set PCRE_NEWLINE_LF
  339          /<bsr_anycrlf>  set PCRE_BSR_ANYCRLF
  340          /<bsr_unicode>  set PCRE_BSR_UNICODE
  341          /<JS>           set PCRE_JAVASCRIPT_COMPAT
  342 
  343 
  344    Perl-compatible modifiers
  345 
  346        The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
  347        PCRE_DOTALL,   or    PCRE_EXTENDED    options,    respectively,    when
  348        pcre[16|32]_compile()  is  called. These four modifier letters have the
  349        same effect as they do in Perl. For example:
  350 
  351          /caseless/i
  352 
  353 
  354    Modifiers for other PCRE options
  355 
  356        The following table shows additional modifiers for  setting  PCRE  com-
  357        pile-time options that do not correspond to anything in Perl:
  358 
  359          /8              PCRE_UTF8           ) when using the 8-bit
  360          /?              PCRE_NO_UTF8_CHECK  )   library
  361 
  362          /8              PCRE_UTF16          ) when using the 16-bit
  363          /?              PCRE_NO_UTF16_CHECK )   library
  364 
  365          /8              PCRE_UTF32          ) when using the 32-bit
  366          /?              PCRE_NO_UTF32_CHECK )   library
  367 
  368          /9              PCRE_NEVER_UTF
  369          /A              PCRE_ANCHORED
  370          /C              PCRE_AUTO_CALLOUT
  371          /E              PCRE_DOLLAR_ENDONLY
  372          /f              PCRE_FIRSTLINE
  373          /J              PCRE_DUPNAMES
  374          /N              PCRE_NO_AUTO_CAPTURE
  375          /O              PCRE_NO_AUTO_POSSESS
  376          /U              PCRE_UNGREEDY
  377          /W              PCRE_UCP
  378          /X              PCRE_EXTRA
  379          /Y              PCRE_NO_START_OPTIMIZE
  380          /<any>          PCRE_NEWLINE_ANY
  381          /<anycrlf>      PCRE_NEWLINE_ANYCRLF
  382          /<cr>           PCRE_NEWLINE_CR
  383          /<crlf>         PCRE_NEWLINE_CRLF
  384          /<lf>           PCRE_NEWLINE_LF
  385          /<bsr_anycrlf>  PCRE_BSR_ANYCRLF
  386          /<bsr_unicode>  PCRE_BSR_UNICODE
  387          /<JS>           PCRE_JAVASCRIPT_COMPAT
  388 
  389        The  modifiers  that are enclosed in angle brackets are literal strings
  390        as shown, including the angle brackets, but the letters within  can  be
  391        in  either case.  This example sets multiline matching with CRLF as the
  392        line ending sequence:
  393 
  394          /^abc/m<CRLF>
  395 
  396        As well as turning on  the  PCRE_UTF8/16/32  option,  the  /8  modifier
  397        causes  all non-printing characters in output strings to be printed us-
  398        ing the \x{hh...} notation. Otherwise, those less than 0x100 are output
  399        in hex without the curly brackets.
  400 
  401        Full  details  of  the PCRE options are given in the pcreapi documenta-
  402        tion.
  403 
  404    Finding all matches in a string
  405 
  406        Searching for all possible matches within each subject  string  can  be
  407        requested  by  the  /g  or  /G modifier. After finding a match, PCRE is
  408        called again to search the remainder of the subject string. The differ-
  409        ence between /g and /G is that the former uses the startoffset argument
  410        to pcre[16|32]_exec() to start searching at a new point within the  en-
  411        tire  string  (which  is  in effect what Perl does), whereas the latter
  412        passes over a shortened substring.  This  makes  a  difference  to  the
  413        matching process if the pattern begins with a lookbehind assertion (in-
  414        cluding \b or \B).
  415 
  416        If any call to pcre[16|32]_exec() in a /g or  /G  sequence  matches  an
  417        empty  string, the next call is done with the PCRE_NOTEMPTY_ATSTART and
  418        PCRE_ANCHORED flags set in order  to  search  for  another,  non-empty,
  419        match  at  the same point. If this second match fails, the start offset
  420        is advanced, and the normal match is retried.  This  imitates  the  way
  421        Perl handles such cases when using the /g modifier or the split() func-
  422        tion. Normally, the start offset is advanced by one character,  but  if
  423        the  newline  convention  recognizes CRLF as a newline, and the current
  424        character is CR followed by LF, an advance of two is used.
  425 
  426    Other modifiers
  427 
  428        There are yet more modifiers for controlling the way pcretest operates.
  429 
  430        The /+ modifier requests that as well as outputting the substring  that
  431        matched  the entire pattern, pcretest should in addition output the re-
  432        mainder of the subject string. This is useful for tests where the  sub-
  433        ject  contains multiple copies of the same substring. If the + modifier
  434        appears twice, the same action is taken  for  captured  substrings.  In
  435        each  case  the  remainder  is output on the following line with a plus
  436        character following the capture number. Note that  this  modifier  must
  437        not  immediately follow the /S modifier because /S+ and /S++ have other
  438        meanings.
  439 
  440        The /= modifier requests that the  values  of  all  potential  captured
  441        parentheses  be  output after a match. By default, only those up to the
  442        highest one actually used in the match are output (corresponding to the
  443        return code from pcre[16|32]_exec()). Values in the offsets vector cor-
  444        responding to higher numbers should be set to -1, and these are  output
  445        as  "<unset>".  This modifier gives a way of checking that this is hap-
  446        pening.
  447 
  448        The /B modifier is a debugging feature. It requests that pcretest  out-
  449        put  a  representation of the compiled code after compilation. Normally
  450        this information contains length and offset values; however, if  /Z  is
  451        also  present,  this data is replaced by spaces. This is a special fea-
  452        ture for use in the automatic test scripts; it ensures  that  the  same
  453        output is generated for different internal link sizes.
  454 
  455        The  /D modifier is a PCRE debugging feature, and is equivalent to /BI,
  456        that is, both the /B and the /I modifiers.
  457 
  458        The /F modifier causes pcretest to flip the byte order  of  the  2-byte
  459        and 4-byte fields in the compiled pattern. This facility is for testing
  460        the feature in PCRE that allows it to execute patterns that  were  com-
  461        piled on a host with a different endianness. This feature is not avail-
  462        able when the POSIX interface to PCRE is being used, that is, when  the
  463        /P pattern modifier is specified. See also the section about saving and
  464        reloading compiled patterns below.
  465 
  466        The /I modifier requests that pcretest  output  information  about  the
  467        compiled  pattern (whether it is anchored, has a fixed first character,
  468        and so on). It does this by calling pcre[16|32]_fullinfo()  after  com-
  469        piling  a  pattern.  If the pattern is studied, the results of that are
  470        also output. In this output, the word "char" means a non-UTF character,
  471        that is, the value of a single data item (8-bit, 16-bit, or 32-bit, de-
  472        pending on the library that is being tested).
  473 
  474        The /K modifier requests pcretest to show names from backtracking  con-
  475        trol  verbs  that  are  returned  from  calls to pcre[16|32]_exec(). It
  476        causes pcretest to create a pcre[16|32]_extra block if one has not  al-
  477        ready  been  created  by  a call to pcre[16|32]_study(), and to set the
  478        PCRE_EXTRA_MARK flag and the mark field  within  it,  every  time  that
  479        pcre[16|32]_exec()  is  called.  If  the  variable  that the mark field
  480        points to is  non-NULL  for  a  match,  non-match,  or  partial  match,
  481        pcretest  prints  the  string  to which it points. For a match, this is
  482        shown on a line by itself, tagged with "MK:". For  a  non-match  it  is
  483        added to the message.
  484 
  485        The  /L modifier must be followed directly by the name of a locale, for
  486        example,
  487 
  488          /pattern/Lfr_FR
  489 
  490        For this reason, it must be the last modifier. The given locale is set,
  491        pcre[16|32]_maketables()  is  called to build a set of character tables
  492        for the locale, and this is then passed to  pcre[16|32]_compile()  when
  493        compiling  the regular expression. Without an /L (or /T) modifier, NULL
  494        is passed as the tables pointer; that is, /L applies only  to  the  ex-
  495        pression on which it appears.
  496 
  497        The  /M  modifier  causes the size in bytes of the memory block used to
  498        hold the compiled pattern to be output. This does not include the  size
  499        of  the  pcre[16|32] block; it is just the actual compiled data. If the
  500        pattern is successfully studied with the PCRE_STUDY_JIT_COMPILE option,
  501        the size of the JIT compiled code is also output.
  502 
  503        The /Q modifier is used to test the use of pcre_stack_guard. It must be
  504        followed by '0' or '1', specifying the return code to be given from  an
  505        external  function  that  is passed to PCRE and used for stack checking
  506        during compilation (see the pcreapi documentation for details).
  507 
  508        The /S modifier causes pcre[16|32]_study() to be called after  the  ex-
  509        pression has been compiled, and the results used when the expression is
  510        matched. There are a number of qualifying characters  that  may  follow
  511        /S.  They may appear in any order.
  512 
  513        If /S is followed by an exclamation mark, pcre[16|32]_study() is called
  514        with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return  a
  515        pcre_extra block, even when studying discovers no useful information.
  516 
  517        If /S is followed by a second S character, it suppresses studying, even
  518        if it was requested externally by the  -s  command  line  option.  This
  519        makes  it possible to specify that certain patterns are always studied,
  520        and others are never studied, independently of -s. This feature is used
  521        in the test files in a few cases where the output is different when the
  522        pattern is studied.
  523 
  524        If the  /S  modifier  is  followed  by  a  +  character,  the  call  to
  525        pcre[16|32]_study()  is made with all the JIT study options, requesting
  526        just-in-time optimization support if it is available, for  both  normal
  527        and  partial matching. If you want to restrict the JIT compiling modes,
  528        you can follow /S+ with a digit in the range 1 to 7:
  529 
  530          1  normal match only
  531          2  soft partial match only
  532          3  normal match and soft partial match
  533          4  hard partial match only
  534          6  soft and hard partial match
  535          7  all three modes (default)
  536 
  537        If /S++ is used instead of /S+ (with or without a following digit), the
  538        text  "(JIT)"  is  added  to  the first output line after a match or no
  539        match when JIT-compiled code was actually used.
  540 
  541        Note that there is also an independent /+  modifier;  it  must  not  be
  542        given immediately after /S or /S+ because this will be misinterpreted.
  543 
  544        If JIT studying is successful, the compiled JIT code will automatically
  545        be used when pcre[16|32]_exec() is run, except when  incompatible  run-
  546        time  options are specified. For more details, see the pcrejit documen-
  547        tation. See also the \J escape sequence below for a way of setting  the
  548        size of the JIT stack.
  549 
  550        Finally,  if  /S  is  followed by a minus character, JIT compilation is
  551        suppressed, even if it was requested externally by the -s command  line
  552        option.  This makes it possible to specify that JIT is never to be used
  553        for certain patterns.
  554 
  555        The /T modifier must be followed by a single digit. It  causes  a  spe-
  556        cific set of built-in character tables to be passed to pcre[16|32]_com-
  557        pile(). It is used in the standard PCRE tests to check  behaviour  with
  558        different character tables. The digit specifies the tables as follows:
  559 
  560          0   the default ASCII tables, as distributed in
  561                pcre_chartables.c.dist
  562          1   a set of tables defining ISO 8859 characters
  563 
  564        In  table 1, some characters whose codes are greater than 128 are iden-
  565        tified as letters, digits, spaces, etc.
  566 
  567    Using the POSIX wrapper API
  568 
  569        The /P modifier causes pcretest to call PCRE via the POSIX wrapper  API
  570        rather  than its native API. This supports only the 8-bit library. When
  571        /P is set, the following modifiers set options for the regcomp()  func-
  572        tion:
  573 
  574          /i    REG_ICASE
  575          /m    REG_NEWLINE
  576          /N    REG_NOSUB
  577          /s    REG_DOTALL     )
  578          /U    REG_UNGREEDY   ) These options are not part of
  579          /W    REG_UCP        )   the POSIX standard
  580          /8    REG_UTF8       )
  581 
  582        The  /+  modifier works as described above. All other modifiers are ig-
  583        nored.
  584 
  585    Locking out certain modifiers
  586 
  587        PCRE can be compiled with or without support for certain features  such
  588        as  UTF-8/16/32  or Unicode properties. Accordingly, the standard tests
  589        are split up into a number of different files  that  are  selected  for
  590        running  depending  on  which features are available. When updating the
  591        tests, it is all too easy to put a new test into the wrong file by mis-
  592        take;  for example, to put a test that requires UTF support into a file
  593        that is used when it is not available. To help detect such mistakes  as
  594        early  as  possible, there is a facility for locking out specific modi-
  595        fiers. If an input line for pcretest starts with the string "< forbid "
  596        the  following  sequence  of characters is taken as a list of forbidden
  597        modifiers. For example, in the test files that must not use UTF or Uni-
  598        code property support, this line appears:
  599 
  600          < forbid 8W
  601 
  602        This  locks out the /8 and /W modifiers. An immediate error is given if
  603        they are subsequently encountered. If the character string  contains  <
  604        but  not  >,  all  the  multi-character modifiers that begin with < are
  605        locked out. Otherwise, such modifiers must be  explicitly  listed,  for
  606        example:
  607 
  608          < forbid <JS><cr>
  609 
  610        There must be a single space between < and "forbid" for this feature to
  611        be recognised. If there is not, the line is interpreted either as a re-
  612        quest to re-load a pre-compiled pattern (see "SAVING AND RELOADING COM-
  613        PILED PATTERNS" below) or, if there is a another < character, as a pat-
  614        tern that uses < as its delimiter.
  615 
  616 
  617 DATA LINES
  618 
  619        Before  each  data  line  is  passed to pcre[16|32]_exec(), leading and
  620        trailing white space is removed, and it is then scanned for \  escapes.
  621        Some  of  these are pretty esoteric features, intended for checking out
  622        some of the more complicated features of PCRE. If you are just  testing
  623        "ordinary"  regular  expressions, you probably don't need any of these.
  624        The following escapes are recognized:
  625 
  626          \a         alarm (BEL, \x07)
  627          \b         backspace (\x08)
  628          \e         escape (\x27)
  629          \f         form feed (\x0c)
  630          \n         newline (\x0a)
  631          \qdd       set the PCRE_MATCH_LIMIT limit to dd
  632                       (any number of digits)
  633          \r         carriage return (\x0d)
  634          \t         tab (\x09)
  635          \v         vertical tab (\x0b)
  636          \nnn       octal character (up to 3 octal digits); always
  637                       a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
  638          \o{dd...}  octal character (any number of octal digits}
  639          \xhh       hexadecimal byte (up to 2 hex digits)
  640          \x{hh...}  hexadecimal character (any number of hex digits)
  641          \A         pass the PCRE_ANCHORED option to pcre[16|32]_exec()
  642                       or pcre[16|32]_dfa_exec()
  643          \B         pass the PCRE_NOTBOL option to pcre[16|32]_exec()
  644                       or pcre[16|32]_dfa_exec()
  645          \Cdd       call pcre[16|32]_copy_substring() for substring dd
  646                       after a successful match (number less than 32)
  647          \Cname     call pcre[16|32]_copy_named_substring() for substring
  648                       "name" after a successful match (name termin-
  649                       ated by next non alphanumeric character)
  650          \C+        show the current captured substrings at callout
  651                       time
  652          \C-        do not supply a callout function
  653          \C!n       return 1 instead of 0 when callout number n is
  654                       reached
  655          \C!n!m     return 1 instead of 0 when callout number n is
  656                       reached for the nth time
  657          \C*n       pass the number n (may be negative) as callout
  658                       data; this is used as the callout return value
  659          \D         use the pcre[16|32]_dfa_exec() match function
  660          \F         only shortest match for pcre[16|32]_dfa_exec()
  661          \Gdd       call pcre[16|32]_get_substring() for substring dd
  662                       after a successful match (number less than 32)
  663          \Gname     call pcre[16|32]_get_named_substring() for substring
  664                       "name" after a successful match (name termin-
  665                       ated by next non-alphanumeric character)
  666          \Jdd       set up a JIT stack of dd kilobytes maximum (any
  667                       number of digits)
  668          \L         call pcre[16|32]_get_substringlist() after a
  669                       successful match
  670          \M         discover the minimum MATCH_LIMIT and
  671                       MATCH_LIMIT_RECURSION settings
  672          \N         pass the PCRE_NOTEMPTY option to pcre[16|32]_exec()
  673                       or pcre[16|32]_dfa_exec(); if used twice, pass the
  674                       PCRE_NOTEMPTY_ATSTART option
  675          \Odd       set the size of the output vector passed to
  676                       pcre[16|32]_exec() to dd (any number of digits)
  677          \P         pass the PCRE_PARTIAL_SOFT option to pcre[16|32]_exec()
  678                       or pcre[16|32]_dfa_exec(); if used twice, pass the
  679                       PCRE_PARTIAL_HARD option
  680          \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
  681                       (any number of digits)
  682          \R         pass the PCRE_DFA_RESTART option to pcre[16|32]_dfa_exec()
  683          \S         output details of memory get/free calls during matching
  684          \Y            pass    the    PCRE_NO_START_OPTIMIZE     option     to
  685        pcre[16|32]_exec()
  686                       or pcre[16|32]_dfa_exec()
  687          \Z         pass the PCRE_NOTEOL option to pcre[16|32]_exec()
  688                       or pcre[16|32]_dfa_exec()
  689          \?         pass the PCRE_NO_UTF[8|16|32]_CHECK option to
  690                       pcre[16|32]_exec() or pcre[16|32]_dfa_exec()
  691          \>dd       start the match at offset dd (optional "-"; then
  692                       any number of digits); this sets the startoffset
  693                       argument         for        pcre[16|32]_exec()        or
  694        pcre[16|32]_dfa_exec()
  695          \<cr>      pass the PCRE_NEWLINE_CR option to pcre[16|32]_exec()
  696                       or pcre[16|32]_dfa_exec()
  697          \<lf>      pass the PCRE_NEWLINE_LF option to pcre[16|32]_exec()
  698                       or pcre[16|32]_dfa_exec()
  699          \<crlf>    pass the PCRE_NEWLINE_CRLF option to pcre[16|32]_exec()
  700                       or pcre[16|32]_dfa_exec()
  701          \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre[16|32]_exec()
  702                       or pcre[16|32]_dfa_exec()
  703          \<any>     pass the PCRE_NEWLINE_ANY option to pcre[16|32]_exec()
  704                       or pcre[16|32]_dfa_exec()
  705 
  706        The use of \x{hh...} is not dependent on the use of the /8 modifier  on
  707        the  pattern. It is recognized always. There may be any number of hexa-
  708        decimal digits inside the braces; invalid  values  provoke  error  mes-
  709        sages.
  710 
  711        Note  that  \xhh  specifies one byte rather than one character in UTF-8
  712        mode; this makes it possible to construct invalid UTF-8  sequences  for
  713        testing  purposes.  On the other hand, \x{hh} is interpreted as a UTF-8
  714        character in UTF-8 mode, generating more than one byte if the value  is
  715        greater  than  127.   When testing the 8-bit library not in UTF-8 mode,
  716        \x{hh} generates one byte for values less than 256, and causes an error
  717        for greater values.
  718 
  719        In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
  720        possible to construct invalid UTF-16 sequences for testing purposes.
  721 
  722        In UTF-32 mode, all 4- to 8-digit \x{...}  values  are  accepted.  This
  723        makes  it  possible  to  construct invalid UTF-32 sequences for testing
  724        purposes.
  725 
  726        The escapes that specify line ending sequences are literal strings, ex-
  727        actly  as  shown. No more than one newline setting should be present in
  728        any data line.
  729 
  730        A backslash followed by anything else just escapes the  anything  else.
  731        If  the very last character is a backslash, it is ignored. This gives a
  732        way of passing an empty line as data, since a real  empty  line  termi-
  733        nates the data input.
  734 
  735        The  \J escape provides a way of setting the maximum stack size that is
  736        used by the just-in-time optimization code. It is ignored if JIT  opti-
  737        mization  is  not being used. Providing a stack that is larger than the
  738        default 32K is necessary only for very complicated patterns.
  739 
  740        If \M is present, pcretest calls pcre[16|32]_exec() several times, with
  741        different values in the match_limit and match_limit_recursion fields of
  742        the pcre[16|32]_extra data structure, until it finds the  minimum  num-
  743        bers for each parameter that allow pcre[16|32]_exec() to complete with-
  744        out error. Because this is testing a specific feature of the normal in-
  745        terpretive  pcre[16|32]_exec()  execution, the use of any JIT optimiza-
  746        tion that might have been set up by the /S+ qualifier of -s+ option  is
  747        disabled.
  748 
  749        The  match_limit number is a measure of the amount of backtracking that
  750        takes place, and checking it out can be instructive.  For  most  simple
  751        matches,  the  number  is quite small, but for patterns with very large
  752        numbers of matching possibilities, it can  become  large  very  quickly
  753        with  increasing  length  of  subject string. The match_limit_recursion
  754        number is a measure of how much stack (or, if  PCRE  is  compiled  with
  755        NO_RECURSE,  how  much heap) memory is needed to complete the match at-
  756        tempt.
  757 
  758        When \O is used, the value specified may be higher or  lower  than  the
  759        size set by the -O command line option (or defaulted to 45); \O applies
  760        only to the call of pcre[16|32]_exec() for the line  in  which  it  ap-
  761        pears.
  762 
  763        If  the /P modifier was present on the pattern, causing the POSIX wrap-
  764        per API to be used, the only option-setting sequences that have any ef-
  765        fect  are \B, \N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NO-
  766        TEOL, respectively, to be passed to regexec().
  767 
  768 
  769 THE ALTERNATIVE MATCHING FUNCTION
  770 
  771        By  default,  pcretest  uses  the  standard  PCRE  matching   function,
  772        pcre[16|32]_exec()  to  match each data line. PCRE also supports an al-
  773        ternative matching function, pcre[16|32]_dfa_test(), which operates  in
  774        a different way, and has some restrictions. The differences between the
  775        two functions are described in the pcrematching documentation.
  776 
  777        If a data line contains the \D escape sequence, or if the command  line
  778        contains  the  -dfa  option, the alternative matching function is used.
  779        This function finds all possible matches at a given point. If, however,
  780        the  \F escape sequence is present in the data line, it stops after the
  781        first match is found. This is always the shortest possible match.
  782 
  783 
  784 DEFAULT OUTPUT FROM PCRETEST
  785 
  786        This section describes the output when the  normal  matching  function,
  787        pcre[16|32]_exec(), is being used.
  788 
  789        When a match succeeds, pcretest outputs the list of captured substrings
  790        that pcre[16|32]_exec() returns, starting with number 0 for the  string
  791        that  matched  the whole pattern. Otherwise, it outputs "No match" when
  792        the return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by  the
  793        partially  matching  substring when pcre[16|32]_exec() returns PCRE_ER-
  794        ROR_PARTIAL. (Note that this is the entire substring that was inspected
  795        during  the  partial match; it may include characters before the actual
  796        match start if a lookbehind assertion, \K, \b, or \B was involved.) For
  797        any other return, pcretest outputs the PCRE negative error number and a
  798        short descriptive phrase. If the error is a failed  UTF  string  check,
  799        the  offset  of  the start of the failing character and the reason code
  800        are also output, provided that the size of  the  output  vector  is  at
  801        least two. Here is an example of an interactive pcretest run.
  802 
  803          $ pcretest
  804          PCRE version 8.13 2011-04-30
  805 
  806            re> /^abc(\d+)/
  807          data> abc123
  808           0: abc123
  809           1: 123
  810          data> xyz
  811          No match
  812 
  813        Unset capturing substrings that are not followed by one that is set are
  814        not returned by pcre[16|32]_exec(), and are not shown by  pcretest.  In
  815        the following example, there are two capturing substrings, but when the
  816        first data line is matched, the second, unset substring is  not  shown.
  817        An  "internal" unset substring is shown as "<unset>", as for the second
  818        data line.
  819 
  820            re> /(a)|(b)/
  821          data> a
  822           0: a
  823           1: a
  824          data> b
  825           0: b
  826           1: <unset>
  827           2: b
  828 
  829        If the strings contain any non-printing characters, they are output  as
  830        \xhh  escapes  if  the  value is less than 256 and UTF mode is not set.
  831        Otherwise they are output as \x{hh...} escapes. See below for the defi-
  832        nition  of non-printing characters. If the pattern has the /+ modifier,
  833        the output for substring 0 is followed by the the rest of  the  subject
  834        string, identified by "0+" like this:
  835 
  836            re> /cat/+
  837          data> cataract
  838           0: cat
  839           0+ aract
  840 
  841        If  the  pattern  has  the /g or /G modifier, the results of successive
  842        matching attempts are output in sequence, like this:
  843 
  844            re> /\Bi(\w\w)/g
  845          data> Mississippi
  846           0: iss
  847           1: ss
  848           0: iss
  849           1: ss
  850           0: ipp
  851           1: pp
  852 
  853        "No match" is output only if the first match attempt fails. Here is  an
  854        example  of a failure message (the offset 4 that is specified by \>4 is
  855        past the end of the subject string):
  856 
  857            re> /xyz/
  858          data> xyz\>4
  859          Error -24 (bad offset value)
  860 
  861        If any of the sequences \C, \G, or \L are present in a data  line  that
  862        is  successfully  matched,  the substrings extracted by the convenience
  863        functions are output with C, G, or L after the string number instead of
  864        a colon. This is in addition to the normal full list. The string length
  865        (that is, the return from the extraction function) is given  in  paren-
  866        theses after each string for \C and \G.
  867 
  868        Note that whereas patterns can be continued over several lines (a plain
  869        ">" prompt is used for continuations), data lines may not. However new-
  870        lines  can  be included in data by means of the \n escape (or \r, \r\n,
  871        etc., depending on the newline sequence setting).
  872 
  873 
  874 OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
  875 
  876        When the alternative matching function, pcre[16|32]_dfa_exec(), is used
  877        (by  means  of the \D escape sequence or the -dfa command line option),
  878        the output consists of a list of all the  matches  that  start  at  the
  879        first point in the subject where there is at least one match. For exam-
  880        ple:
  881 
  882            re> /(tang|tangerine|tan)/
  883          data> yellow tangerine\D
  884           0: tangerine
  885           1: tang
  886           2: tan
  887 
  888        (Using the normal matching function on this data  finds  only  "tang".)
  889        The  longest matching string is always given first (and numbered zero).
  890        After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
  891        lowed  by  the partially matching substring. (Note that this is the en-
  892        tire substring that was inspected during the partial match; it may  in-
  893        clude  characters  before the actual match start if a lookbehind asser-
  894        tion, \K, \b, or \B was involved.)
  895 
  896        If /g is present on the pattern, the search for further matches resumes
  897        at the end of the longest match. For example:
  898 
  899            re> /(tang|tangerine|tan)/g
  900          data> yellow tangerine and tangy sultana\D
  901           0: tangerine
  902           1: tang
  903           2: tan
  904           0: tang
  905           1: tan
  906           0: tan
  907 
  908        Since the matching function does not support substring capture, the es-
  909        cape sequences that are concerned with captured substrings are not rel-
  910        evant.
  911 
  912 
  913 RESTARTING AFTER A PARTIAL MATCH
  914 
  915        When the alternative matching function has given the PCRE_ERROR_PARTIAL
  916        return, indicating that the subject partially matched the pattern,  you
  917        can  restart  the match with additional subject data by means of the \R
  918        escape sequence. For example:
  919 
  920            re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
  921          data> 23ja\P\D
  922          Partial match: 23ja
  923          data> n05\R\D
  924           0: n05
  925 
  926        For further information about partial  matching,  see  the  pcrepartial
  927        documentation.
  928 
  929 
  930 CALLOUTS
  931 
  932        If  the pattern contains any callout requests, pcretest's callout func-
  933        tion is called during matching. This works  with  both  matching  func-
  934        tions. By default, the called function displays the callout number, the
  935        start and current positions in the text at the callout  time,  and  the
  936        next pattern item to be tested. For example:
  937 
  938          --->pqrabcdef
  939            0    ^  ^     \d
  940 
  941        This  output  indicates  that callout number 0 occurred for a match at-
  942        tempt starting at the fourth character of the subject string, when  the
  943        pointer  was  at  the  seventh character of the data, and when the next
  944        pattern item was \d. Just one circumflex is output  if  the  start  and
  945        current positions are the same.
  946 
  947        Callouts numbered 255 are assumed to be automatic callouts, inserted as
  948        a result of the /C pattern modifier. In this case, instead  of  showing
  949        the  callout  number, the offset in the pattern, preceded by a plus, is
  950        output. For example:
  951 
  952            re> /\d?[A-E]\*/C
  953          data> E*
  954          --->E*
  955           +0 ^      \d?
  956           +3 ^      [A-E]
  957           +8 ^^     \*
  958          +10 ^ ^
  959           0: E*
  960 
  961        If a pattern contains (*MARK) items, an additional line is output when-
  962        ever a change of latest mark is passed to the callout function. For ex-
  963        ample:
  964 
  965            re> /a(*MARK:X)bc/C
  966          data> abc
  967          --->abc
  968           +0 ^       a
  969           +1 ^^      (*MARK:X)
  970          +10 ^^      b
  971          Latest Mark: X
  972          +11 ^ ^     c
  973          +12 ^  ^
  974           0: abc
  975 
  976        The mark changes between matching "a" and "b", but stays the  same  for
  977        the  rest  of  the match, so nothing more is output. If, as a result of
  978        backtracking, the mark reverts to being unset, the  text  "<unset>"  is
  979        output.
  980 
  981        The  callout  function  in pcretest returns zero (carry on matching) by
  982        default, but you can use a \C item in a data line (as described  above)
  983        to change this and other parameters of the callout.
  984 
  985        Inserting  callouts can be helpful when using pcretest to check compli-
  986        cated regular expressions. For further information about callouts,  see
  987        the pcrecallout documentation.
  988 
  989 
  990 NON-PRINTING CHARACTERS
  991 
  992        When  pcretest is outputting text in the compiled version of a pattern,
  993        bytes other than 32-126 are always treated as  non-printing  characters
  994        are are therefore shown as hex escapes.
  995 
  996        When  pcretest  is  outputting text that is a matched part of a subject
  997        string, it behaves in the same way, unless a different locale has  been
  998        set  for  the  pattern  (using  the /L modifier). In this case, the is-
  999        print() function to distinguish printing and non-printing characters.
 1000 
 1001 
 1002 SAVING AND RELOADING COMPILED PATTERNS
 1003 
 1004        The facilities described in this section are  not  available  when  the
 1005        POSIX  interface  to  PCRE  is being used, that is, when the /P pattern
 1006        modifier is specified.
 1007 
 1008        When the POSIX interface is not in use, you can cause pcretest to write
 1009        a  compiled  pattern to a file, by following the modifiers with > and a
 1010        file name.  For example:
 1011 
 1012          /pattern/im >/some/file
 1013 
 1014        See the pcreprecompile documentation for a discussion about saving  and
 1015        re-using  compiled patterns.  Note that if the pattern was successfully
 1016        studied with JIT optimization, the JIT data cannot be saved.
 1017 
 1018        The data that is written is binary.  The  first  eight  bytes  are  the
 1019        length  of  the compiled pattern data followed by the length of the op-
 1020        tional study data, each written as four bytes in big-endian order (most
 1021        significant  byte first). If there is no study data (either the pattern
 1022        was not studied, or studying did  not  return  any  data),  the  second
 1023        length  is  zero. The lengths are followed by an exact copy of the com-
 1024        piled pattern. If there is additional study data, this  (excluding  any
 1025        JIT data) follows immediately after the compiled pattern. After writing
 1026        the file, pcretest expects to read a new pattern.
 1027 
 1028        A saved pattern can be reloaded into pcretest by  specifying  <  and  a
 1029        file  name  instead  of a pattern. There must be no space between < and
 1030        the file name, which must not  contain  a  <  character,  as  otherwise
 1031        pcretest  will  interpret  the line as a pattern delimited by < charac-
 1032        ters. For example:
 1033 
 1034           re> </some/file
 1035          Compiled pattern loaded from /some/file
 1036          No study data
 1037 
 1038        If the pattern was previously studied with the  JIT  optimization,  the
 1039        JIT  information cannot be saved and restored, and so is lost. When the
 1040        pattern has been loaded, pcretest proceeds to read data  lines  in  the
 1041        usual way.
 1042 
 1043        You  can copy a file written by pcretest to a different host and reload
 1044        it there, even if the new host has opposite endianness to  the  one  on
 1045        which  the pattern was compiled. For example, you can compile on an i86
 1046        machine and run on a SPARC machine. When a pattern  is  reloaded  on  a
 1047        host with different endianness, the confirmation message is changed to:
 1048 
 1049          Compiled pattern (byte-inverted) loaded from /some/file
 1050 
 1051        The test suite contains some saved pre-compiled patterns with different
 1052        endianness. These are reloaded using "<!" instead  of  just  "<".  This
 1053        suppresses the "(byte-inverted)" text so that the output is the same on
 1054        all hosts. It also forces debugging output once the  pattern  has  been
 1055        reloaded.
 1056 
 1057        File  names  for  saving and reloading can be absolute or relative, but
 1058        note that the shell facility of expanding a file name that starts  with
 1059        a tilde (~) is not available.
 1060 
 1061        The  ability to save and reload files in pcretest is intended for test-
 1062        ing and experimentation. It is not intended for production use  because
 1063        only  a  single pattern can be written to a file. Furthermore, there is
 1064        no facility for supplying  custom  character  tables  for  use  with  a
 1065        reloaded  pattern. If the original pattern was compiled with custom ta-
 1066        bles, an attempt to match a subject string using a reloaded pattern  is
 1067        likely  to  cause pcretest to crash.  Finally, if you attempt to load a
 1068        file that is not in the correct format, the result is undefined.
 1069 
 1070 
 1071 SEE ALSO
 1072 
 1073        pcre(3), pcre16(3),  pcre32(3),  pcreapi(3),  pcrecallout(3),  pcrejit,
 1074        pcrematching(3), pcrepartial(d), pcrepattern(3), pcreprecompile(3).
 1075 
 1076 
 1077 AUTHOR
 1078 
 1079        Philip Hazel
 1080        University Computing Service
 1081        Cambridge CB2 3QH, England.
 1082 
 1083 
 1084 REVISION
 1085 
 1086        Last updated: 10 February 2020
 1087        Copyright (c) 1997-2020 University of Cambridge.