Annotation of embedaddon/pcre/doc/pcretest.txt, revision 1.1.1.5

1.1.1.4   misho       1: PCRETEST(1)                 General Commands Manual                PCRETEST(1)
                      2: 
1.1       misho       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
1.1.1.4   misho      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
1.1.1.2   misho      33: 
1.1.1.4   misho      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.
1.1.1.2   misho      41: 
1.1.1.4   misho      42: 
                     43: PCRE's 8-BIT, 16-BIT AND 32-BIT LIBRARIES
1.1.1.2   misho      44: 
                     45:        From release 8.30, two separate PCRE libraries can be built. The origi-
                     46:        nal  one  supports  8-bit  character  strings, whereas the newer 16-bit
1.1.1.4   misho      47:        library supports  character  strings  encoded  in  16-bit  units.  From
                     48:        release  8.32,  a  third  library  can  be  built, supporting character
                     49:        strings encoded in 32-bit units. The pcretest program can  be  used  to
                     50:        test all three libraries. However, it is itself still an 8-bit program,
                     51:        reading 8-bit input and writing 8-bit output.  When testing the  16-bit
                     52:        or  32-bit  library, the patterns and data strings are converted to 16-
                     53:        or 32-bit format before being passed to  the  PCRE  library  functions.
                     54:        Results are converted to 8-bit for output.
                     55: 
                     56:        References to functions and structures of the form pcre[16|32]_xx below
                     57:        mean "pcre_xx when using the 8-bit library, pcre16_xx  when  using  the
                     58:        16-bit library, or pcre32_xx when using the 32-bit library".
1.1       misho      59: 
                     60: 
                     61: COMMAND LINE OPTIONS
                     62: 
1.1.1.4   misho      63:        -8        If  both the 8-bit library has been built, this option causes
                     64:                  the 8-bit library to be used (which is the default);  if  the
                     65:                  8-bit  library  has  not  been  built,  this option causes an
                     66:                  error.
                     67: 
                     68:        -16       If both the 8-bit or the 32-bit,  and  the  16-bit  libraries
                     69:                  have  been built, this option causes the 16-bit library to be
                     70:                  used. If only the 16-bit library has been built, this is  the
                     71:                  default  (so  has no effect). If only the 8-bit or the 32-bit
                     72:                  library has been built, this option causes an error.
                     73: 
                     74:        -32       If both the 8-bit or the 16-bit,  and  the  32-bit  libraries
                     75:                  have  been built, this option causes the 32-bit library to be
                     76:                  used. If only the 32-bit library has been built, this is  the
                     77:                  default  (so  has no effect). If only the 8-bit or the 16-bit
                     78:                  library has been built, this option causes an error.
1.1.1.2   misho      79: 
1.1.1.4   misho      80:        -b        Behave as if each pattern has the /B (show byte  code)  modi-
1.1       misho      81:                  fier; the internal form is output after compilation.
                     82: 
                     83:        -C        Output the version number of the PCRE library, and all avail-
1.1.1.4   misho      84:                  able  information  about  the  optional  features  that   are
                     85:                  included,  and  then  exit  with  zero  exit  code. All other
                     86:                  options are ignored.
1.1.1.2   misho      87: 
                     88:        -C option Output information about a specific build-time  option,  then
                     89:                  exit.  This functionality is intended for use in scripts such
1.1.1.4   misho      90:                  as RunTest. The following options output the  value  and  set
                     91:                  the exit code as indicated:
1.1.1.2   misho      92: 
1.1.1.4   misho      93:                    ebcdic-nl  the code for LF (= NL) in an EBCDIC environment:
                     94:                                 0x15 or 0x25
                     95:                                 0 if used in an ASCII environment
                     96:                                 exit code is always 0
                     97:                    linksize   the configured internal link size (2, 3, or 4)
                     98:                                 exit code is set to the link size
1.1.1.2   misho      99:                    newline    the default newline setting:
                    100:                                 CR, LF, CRLF, ANYCRLF, or ANY
1.1.1.4   misho     101:                                 exit code is always 0
1.1.1.2   misho     102: 
1.1.1.4   misho     103:                  The  following  options output 1 for true or 0 for false, and
                    104:                  set the exit code to the same value:
1.1.1.2   misho     105: 
1.1.1.4   misho     106:                    ebcdic     compiled for an EBCDIC environment
1.1.1.2   misho     107:                    jit        just-in-time support is available
                    108:                    pcre16     the 16-bit library was built
1.1.1.4   misho     109:                    pcre32     the 32-bit library was built
1.1.1.2   misho     110:                    pcre8      the 8-bit library was built
                    111:                    ucp        Unicode property support is available
1.1.1.4   misho     112:                    utf        UTF-8 and/or UTF-16 and/or UTF-32 support
                    113:                                 is available
                    114: 
                    115:                  If an unknown option is given, an error  message  is  output;
                    116:                  the exit code is 0.
1.1       misho     117: 
1.1.1.4   misho     118:        -d        Behave  as  if  each pattern has the /D (debug) modifier; the
                    119:                  internal form and information about the compiled  pattern  is
1.1       misho     120:                  output after compilation; -d is equivalent to -b -i.
                    121: 
1.1.1.4   misho     122:        -dfa      Behave  as if each data line contains the \D escape sequence;
1.1       misho     123:                  this    causes    the    alternative    matching    function,
1.1.1.4   misho     124:                  pcre[16|32]_dfa_exec(),  to  be  used instead of the standard
                    125:                  pcre[16|32]_exec() function (more detail is given below).
1.1       misho     126: 
                    127:        -help     Output a brief summary these options and then exit.
                    128: 
1.1.1.4   misho     129:        -i        Behave as if each pattern has the  /I  modifier;  information
1.1       misho     130:                  about the compiled pattern is given after compilation.
                    131: 
1.1.1.4   misho     132:        -M        Behave  as if each data line contains the \M escape sequence;
                    133:                  this causes PCRE to  discover  the  minimum  MATCH_LIMIT  and
                    134:                  MATCH_LIMIT_RECURSION  settings by calling pcre[16|32]_exec()
1.1.1.2   misho     135:                  repeatedly with different limits.
                    136: 
1.1.1.4   misho     137:        -m        Output the size of each compiled pattern after  it  has  been
                    138:                  compiled.  This  is  equivalent  to adding /M to each regular
1.1.1.2   misho     139:                  expression. The size is given in bytes for both libraries.
                    140: 
1.1.1.5 ! misho     141:        -O        Behave as if each pattern has the /O modifier, that  is  dis-
        !           142:                  able auto-possessification for all patterns.
        !           143: 
        !           144:        -o osize  Set  the number of elements in the output vector that is used
        !           145:                  when calling pcre[16|32]_exec() or pcre[16|32]_dfa_exec()  to
        !           146:                  be  osize.  The  default  value is 45, which is enough for 14
1.1.1.4   misho     147:                  capturing subexpressions for pcre[16|32]_exec() or 22 differ-
1.1.1.5 ! misho     148:                  ent  matches for pcre[16|32]_dfa_exec().  The vector size can
        !           149:                  be changed for individual matching calls by including  \O  in
1.1.1.4   misho     150:                  the data line (see below).
                    151: 
1.1.1.5 ! misho     152:        -p        Behave  as  if  each  pattern  has the /P modifier; the POSIX
        !           153:                  wrapper API is used to call PCRE. None of the  other  options
        !           154:                  has  any  effect when -p is set. This option can be used only
1.1.1.2   misho     155:                  with the 8-bit library.
1.1       misho     156: 
1.1.1.5 ! misho     157:        -q        Do not output the version number of pcretest at the start  of
1.1       misho     158:                  execution.
                    159: 
1.1.1.5 ! misho     160:        -S size   On  Unix-like  systems, set the size of the run-time stack to
1.1       misho     161:                  size megabytes.
                    162: 
1.1.1.5 ! misho     163:        -s or -s+ Behave as if each pattern  has  the  /S  modifier;  in  other
        !           164:                  words,  force each pattern to be studied. If -s+ is used, all
        !           165:                  the JIT compile options are  passed  to  pcre[16|32]_study(),
        !           166:                  causing  just-in-time  optimization  to  be  set  up if it is
        !           167:                  available, for both full and partial matching.  Specific  JIT
1.1.1.4   misho     168:                  compile options can be selected by following -s+ with a digit
1.1.1.5 ! misho     169:                  in the range 1 to 7, which selects the JIT compile  modes  as
1.1.1.4   misho     170:                  follows:
1.1.1.3   misho     171: 
                    172:                    1  normal match only
                    173:                    2  soft partial match only
                    174:                    3  normal match and soft partial match
                    175:                    4  hard partial match only
                    176:                    6  soft and hard partial match
                    177:                    7  all three modes (default)
                    178: 
1.1.1.5 ! misho     179:                  If  -s++  is used instead of -s+ (with or without a following
        !           180:                  digit), the text "(JIT)" is added to the  first  output  line
1.1.1.3   misho     181:                  after a match or no match when JIT-compiled code was actually
                    182:                  used.
                    183: 
1.1.1.5 ! misho     184:                  Note that there are pattern options  that  can  override  -s,
1.1.1.4   misho     185:                  either specifying no studying at all, or suppressing JIT com-
                    186:                  pilation.
                    187: 
1.1.1.5 ! misho     188:                  If the /I or /D option is present on  a  pattern  (requesting
        !           189:                  output  about  the  compiled  pattern), information about the
        !           190:                  result of studying is not included when  studying  is  caused
        !           191:                  only  by  -s  and neither -i nor -d is present on the command
        !           192:                  line. This behaviour means that the output  from  tests  that
        !           193:                  are  run with and without -s should be identical, except when
1.1.1.4   misho     194:                  options that output information about the actual running of a
                    195:                  match are set.
                    196: 
1.1.1.5 ! misho     197:                  The  -M,  -t,  and  -tm options, which give information about
        !           198:                  resources used, are likely to produce different  output  with
        !           199:                  and  without  -s.  Output may also differ if the /C option is
1.1.1.4   misho     200:                  present on an individual pattern. This uses callouts to trace
1.1.1.5 ! misho     201:                  the  the  matching process, and this may be different between
        !           202:                  studied and non-studied patterns.  If  the  pattern  contains
        !           203:                  (*MARK)  items  there  may  also be differences, for the same
1.1.1.4   misho     204:                  reason. The -s command line option can be overridden for spe-
1.1.1.5 ! misho     205:                  cific  patterns that should never be studied (see the /S pat-
1.1.1.4   misho     206:                  tern modifier below).
1.1.1.3   misho     207: 
1.1.1.5 ! misho     208:        -t        Run each compile, study, and match many times with  a  timer,
        !           209:                  and  output  the resulting times per compile, study, or match
        !           210:                  (in milliseconds). Do not set -m with -t,  because  you  will
        !           211:                  then get the size output a zillion times, and the timing will
        !           212:                  be distorted. You can control the number of  iterations  that
        !           213:                  are used for timing by following -t with a number (as a sepa-
        !           214:                  rate item on the command line). For example, "-t 1000"  iter-
        !           215:                  ates 1000 times.  The default is to iterate 500000 times.
1.1       misho     216: 
                    217:        -tm       This is like -t except that it times only the matching phase,
                    218:                  not the compile or study phases.
                    219: 
1.1.1.5 ! misho     220:        -T -TM    These behave like -t and -tm, but in addition, at the end  of
        !           221:                  a run, the total times for all compiles, studies, and matches
        !           222:                  are output.
        !           223: 
1.1       misho     224: 
                    225: DESCRIPTION
                    226: 
1.1.1.5 ! misho     227:        If pcretest is given two filename arguments, it reads  from  the  first
1.1       misho     228:        and writes to the second. If it is given only one filename argument, it
1.1.1.5 ! misho     229:        reads from that file and writes to stdout.  Otherwise,  it  reads  from
        !           230:        stdin  and  writes to stdout, and prompts for each line of input, using
1.1       misho     231:        "re>" to prompt for regular expressions, and "data>" to prompt for data
                    232:        lines.
                    233: 
1.1.1.5 ! misho     234:        When  pcretest  is  built,  a  configuration option can specify that it
        !           235:        should be linked with the libreadline library. When this  is  done,  if
1.1       misho     236:        the input is from a terminal, it is read using the readline() function.
1.1.1.5 ! misho     237:        This provides line-editing and history facilities. The output from  the
1.1       misho     238:        -help option states whether or not readline() will be used.
                    239: 
                    240:        The program handles any number of sets of input on a single input file.
1.1.1.5 ! misho     241:        Each set starts with a regular expression, and continues with any  num-
        !           242:        ber of data lines to be matched against that pattern.
1.1       misho     243: 
1.1.1.5 ! misho     244:        Each  data line is matched separately and independently. If you want to
1.1       misho     245:        do multi-line matches, you have to use the \n escape sequence (or \r or
                    246:        \r\n, etc., depending on the newline setting) in a single line of input
1.1.1.5 ! misho     247:        to encode the newline sequences. There is no limit  on  the  length  of
        !           248:        data  lines;  the  input  buffer is automatically extended if it is too
1.1       misho     249:        small.
                    250: 
1.1.1.5 ! misho     251:        An empty line signals the end of the data lines, at which point  a  new
        !           252:        regular  expression is read. The regular expressions are given enclosed
1.1       misho     253:        in any non-alphanumeric delimiters other than backslash, for example:
                    254: 
                    255:          /(a|bc)x+yz/
                    256: 
1.1.1.5 ! misho     257:        White space before the initial delimiter is ignored. A regular  expres-
        !           258:        sion  may be continued over several input lines, in which case the new-
        !           259:        line characters are included within it. It is possible to  include  the
1.1       misho     260:        delimiter within the pattern by escaping it, for example
                    261: 
                    262:          /abc\/def/
                    263: 
1.1.1.5 ! misho     264:        If  you  do  so, the escape and the delimiter form part of the pattern,
        !           265:        but since delimiters are always non-alphanumeric, this does not  affect
        !           266:        its  interpretation.   If the terminating delimiter is immediately fol-
1.1       misho     267:        lowed by a backslash, for example,
                    268: 
                    269:          /abc/\
                    270: 
1.1.1.5 ! misho     271:        then a backslash is added to the end of the pattern. This  is  done  to
        !           272:        provide  a  way of testing the error condition that arises if a pattern
1.1       misho     273:        finishes with a backslash, because
                    274: 
                    275:          /abc\/
                    276: 
1.1.1.5 ! misho     277:        is interpreted as the first line of a pattern that starts with  "abc/",
1.1       misho     278:        causing pcretest to read the next line as a continuation of the regular
                    279:        expression.
                    280: 
                    281: 
                    282: PATTERN MODIFIERS
                    283: 
1.1.1.5 ! misho     284:        A pattern may be followed by any number of modifiers, which are  mostly
        !           285:        single  characters,  though  some  of these can be qualified by further
        !           286:        characters.  Following Perl usage, these are referred to below as,  for
        !           287:        example,  "the  /i  modifier", even though the delimiter of the pattern
        !           288:        need not always be a slash, and no slash is  used  when  writing  modi-
        !           289:        fiers.  White  space may appear between the final pattern delimiter and
        !           290:        the first modifier, and between the modifiers  themselves.  For  refer-
        !           291:        ence,  here  is  a  complete  list of modifiers. They fall into several
1.1.1.4   misho     292:        groups that are described in detail in the following sections.
                    293: 
                    294:          /8              set UTF mode
                    295:          /9              set PCRE_NEVER_UTF (locks out UTF mode)
                    296:          /?              disable UTF validity check
                    297:          /+              show remainder of subject after match
                    298:          /=              show all captures (not just those that are set)
                    299: 
                    300:          /A              set PCRE_ANCHORED
                    301:          /B              show compiled code
                    302:          /C              set PCRE_AUTO_CALLOUT
                    303:          /D              same as /B plus /I
                    304:          /E              set PCRE_DOLLAR_ENDONLY
                    305:          /F              flip byte order in compiled pattern
                    306:          /f              set PCRE_FIRSTLINE
                    307:          /G              find all matches (shorten string)
                    308:          /g              find all matches (use startoffset)
                    309:          /I              show information about pattern
                    310:          /i              set PCRE_CASELESS
                    311:          /J              set PCRE_DUPNAMES
                    312:          /K              show backtracking control names
                    313:          /L              set locale
                    314:          /M              show compiled memory size
                    315:          /m              set PCRE_MULTILINE
                    316:          /N              set PCRE_NO_AUTO_CAPTURE
1.1.1.5 ! misho     317:          /O              set PCRE_NO_AUTO_POSSESS
1.1.1.4   misho     318:          /P              use the POSIX wrapper
                    319:          /S              study the pattern after compilation
                    320:          /s              set PCRE_DOTALL
                    321:          /T              select character tables
                    322:          /U              set PCRE_UNGREEDY
                    323:          /W              set PCRE_UCP
                    324:          /X              set PCRE_EXTRA
                    325:          /x              set PCRE_EXTENDED
                    326:          /Y              set PCRE_NO_START_OPTIMIZE
                    327:          /Z              don't show lengths in /B output
                    328: 
                    329:          /<any>          set PCRE_NEWLINE_ANY
                    330:          /<anycrlf>      set PCRE_NEWLINE_ANYCRLF
                    331:          /<cr>           set PCRE_NEWLINE_CR
                    332:          /<crlf>         set PCRE_NEWLINE_CRLF
                    333:          /<lf>           set PCRE_NEWLINE_LF
                    334:          /<bsr_anycrlf>  set PCRE_BSR_ANYCRLF
                    335:          /<bsr_unicode>  set PCRE_BSR_UNICODE
                    336:          /<JS>           set PCRE_JAVASCRIPT_COMPAT
                    337: 
                    338: 
                    339:    Perl-compatible modifiers
1.1       misho     340: 
                    341:        The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
1.1.1.5 ! misho     342:        PCRE_DOTALL,    or    PCRE_EXTENDED    options,    respectively,   when
        !           343:        pcre[16|32]_compile() is called. These four modifier letters  have  the
1.1.1.4   misho     344:        same effect as they do in Perl. For example:
1.1       misho     345: 
                    346:          /caseless/i
                    347: 
1.1.1.4   misho     348: 
                    349:    Modifiers for other PCRE options
                    350: 
1.1.1.5 ! misho     351:        The  following  table  shows additional modifiers for setting PCRE com-
1.1       misho     352:        pile-time options that do not correspond to anything in Perl:
                    353: 
1.1.1.2   misho     354:          /8              PCRE_UTF8           ) when using the 8-bit
                    355:          /?              PCRE_NO_UTF8_CHECK  )   library
                    356: 
                    357:          /8              PCRE_UTF16          ) when using the 16-bit
                    358:          /?              PCRE_NO_UTF16_CHECK )   library
                    359: 
1.1.1.4   misho     360:          /8              PCRE_UTF32          ) when using the 32-bit
                    361:          /?              PCRE_NO_UTF32_CHECK )   library
                    362: 
                    363:          /9              PCRE_NEVER_UTF
1.1       misho     364:          /A              PCRE_ANCHORED
                    365:          /C              PCRE_AUTO_CALLOUT
                    366:          /E              PCRE_DOLLAR_ENDONLY
                    367:          /f              PCRE_FIRSTLINE
                    368:          /J              PCRE_DUPNAMES
                    369:          /N              PCRE_NO_AUTO_CAPTURE
1.1.1.5 ! misho     370:          /O              PCRE_NO_AUTO_POSSESS
1.1       misho     371:          /U              PCRE_UNGREEDY
                    372:          /W              PCRE_UCP
                    373:          /X              PCRE_EXTRA
                    374:          /Y              PCRE_NO_START_OPTIMIZE
1.1.1.4   misho     375:          /<any>          PCRE_NEWLINE_ANY
                    376:          /<anycrlf>      PCRE_NEWLINE_ANYCRLF
1.1       misho     377:          /<cr>           PCRE_NEWLINE_CR
                    378:          /<crlf>         PCRE_NEWLINE_CRLF
1.1.1.4   misho     379:          /<lf>           PCRE_NEWLINE_LF
1.1       misho     380:          /<bsr_anycrlf>  PCRE_BSR_ANYCRLF
                    381:          /<bsr_unicode>  PCRE_BSR_UNICODE
1.1.1.4   misho     382:          /<JS>           PCRE_JAVASCRIPT_COMPAT
1.1       misho     383: 
1.1.1.5 ! misho     384:        The modifiers that are enclosed in angle brackets are  literal  strings
        !           385:        as  shown,  including the angle brackets, but the letters within can be
        !           386:        in either case.  This example sets multiline matching with CRLF as  the
1.1       misho     387:        line ending sequence:
                    388: 
                    389:          /^abc/m<CRLF>
                    390: 
1.1.1.5 ! misho     391:        As  well  as  turning  on  the  PCRE_UTF8/16/32 option, the /8 modifier
        !           392:        causes all non-printing characters in  output  strings  to  be  printed
1.1.1.4   misho     393:        using the \x{hh...} notation. Otherwise, those less than 0x100 are out-
                    394:        put in hex without the curly brackets.
1.1.1.2   misho     395: 
1.1.1.5 ! misho     396:        Full details of the PCRE options are given in  the  pcreapi  documenta-
1.1.1.2   misho     397:        tion.
1.1       misho     398: 
                    399:    Finding all matches in a string
                    400: 
1.1.1.5 ! misho     401:        Searching  for  all  possible matches within each subject string can be
        !           402:        requested by the /g or /G modifier. After  finding  a  match,  PCRE  is
1.1       misho     403:        called again to search the remainder of the subject string. The differ-
                    404:        ence between /g and /G is that the former uses the startoffset argument
1.1.1.5 ! misho     405:        to  pcre[16|32]_exec()  to  start  searching  at a new point within the
        !           406:        entire string (which is in effect what Perl does), whereas  the  latter
        !           407:        passes  over  a  shortened  substring.  This  makes a difference to the
        !           408:        matching process if the pattern  begins  with  a  lookbehind  assertion
1.1.1.4   misho     409:        (including \b or \B).
                    410: 
1.1.1.5 ! misho     411:        If  any  call  to  pcre[16|32]_exec() in a /g or /G sequence matches an
        !           412:        empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART  and
        !           413:        PCRE_ANCHORED  flags  set  in  order  to search for another, non-empty,
        !           414:        match at the same point. If this second match fails, the  start  offset
        !           415:        is  advanced,  and  the  normal match is retried. This imitates the way
1.1       misho     416:        Perl handles such cases when using the /g modifier or the split() func-
1.1.1.5 ! misho     417:        tion.  Normally,  the start offset is advanced by one character, but if
        !           418:        the newline convention recognizes CRLF as a newline,  and  the  current
1.1       misho     419:        character is CR followed by LF, an advance of two is used.
                    420: 
                    421:    Other modifiers
                    422: 
                    423:        There are yet more modifiers for controlling the way pcretest operates.
                    424: 
1.1.1.5 ! misho     425:        The  /+ modifier requests that as well as outputting the substring that
        !           426:        matched the entire pattern, pcretest  should  in  addition  output  the
        !           427:        remainder  of  the  subject  string. This is useful for tests where the
        !           428:        subject contains multiple copies of the same substring. If the +  modi-
        !           429:        fier  appears  twice, the same action is taken for captured substrings.
        !           430:        In each case the remainder is output on the following line with a  plus
        !           431:        character  following  the  capture number. Note that this modifier must
        !           432:        not immediately follow the /S modifier because /S+ and /S++ have  other
1.1.1.3   misho     433:        meanings.
1.1       misho     434: 
1.1.1.5 ! misho     435:        The  /=  modifier  requests  that  the values of all potential captured
        !           436:        parentheses be output after a match. By default, only those up  to  the
1.1.1.2   misho     437:        highest one actually used in the match are output (corresponding to the
1.1.1.4   misho     438:        return code from pcre[16|32]_exec()). Values in the offsets vector cor-
1.1.1.5 ! misho     439:        responding  to higher numbers should be set to -1, and these are output
        !           440:        as "<unset>". This modifier gives a way of checking that this  is  hap-
1.1.1.4   misho     441:        pening.
                    442: 
1.1.1.5 ! misho     443:        The  /B modifier is a debugging feature. It requests that pcretest out-
        !           444:        put a representation of the compiled code after  compilation.  Normally
        !           445:        this  information  contains length and offset values; however, if /Z is
        !           446:        also present, this data is replaced by spaces. This is a  special  fea-
        !           447:        ture  for  use  in the automatic test scripts; it ensures that the same
1.1       misho     448:        output is generated for different internal link sizes.
                    449: 
1.1.1.5 ! misho     450:        The /D modifier is a PCRE debugging feature, and is equivalent to  /BI,
1.1       misho     451:        that is, both the /B and the /I modifiers.
                    452: 
1.1.1.5 ! misho     453:        The  /F  modifier  causes pcretest to flip the byte order of the 2-byte
1.1.1.2   misho     454:        and 4-byte fields in the compiled pattern. This facility is for testing
1.1.1.5 ! misho     455:        the  feature  in PCRE that allows it to execute patterns that were com-
1.1.1.2   misho     456:        piled on a host with a different endianness. This feature is not avail-
1.1.1.5 ! misho     457:        able  when the POSIX interface to PCRE is being used, that is, when the
1.1.1.2   misho     458:        /P pattern modifier is specified. See also the section about saving and
                    459:        reloading compiled patterns below.
                    460: 
1.1.1.5 ! misho     461:        The  /I  modifier  requests  that pcretest output information about the
        !           462:        compiled pattern (whether it is anchored, has a fixed first  character,
        !           463:        and  so  on). It does this by calling pcre[16|32]_fullinfo() after com-
        !           464:        piling a pattern. If the pattern is studied, the results  of  that  are
1.1.1.4   misho     465:        also output.
                    466: 
1.1.1.5 ! misho     467:        The  /K modifier requests pcretest to show names from backtracking con-
        !           468:        trol verbs that are  returned  from  calls  to  pcre[16|32]_exec().  It
        !           469:        causes  pcretest  to  create  a  pcre[16|32]_extra block if one has not
        !           470:        already been created by a call to pcre[16|32]_study(), and to  set  the
        !           471:        PCRE_EXTRA_MARK  flag  and  the  mark  field within it, every time that
        !           472:        pcre[16|32]_exec() is called. If  the  variable  that  the  mark  field
        !           473:        points  to  is  non-NULL  for  a  match,  non-match,  or partial match,
        !           474:        pcretest prints the string to which it points. For  a  match,  this  is
        !           475:        shown  on  a  line  by itself, tagged with "MK:". For a non-match it is
1.1.1.4   misho     476:        added to the message.
1.1       misho     477: 
1.1.1.5 ! misho     478:        The /L modifier must be followed directly by the name of a locale,  for
1.1       misho     479:        example,
                    480: 
                    481:          /pattern/Lfr_FR
                    482: 
                    483:        For this reason, it must be the last modifier. The given locale is set,
1.1.1.5 ! misho     484:        pcre[16|32]_maketables() is called to build a set of  character  tables
        !           485:        for  the  locale, and this is then passed to pcre[16|32]_compile() when
        !           486:        compiling the regular expression. Without an /L (or /T) modifier,  NULL
        !           487:        is  passed  as  the  tables  pointer;  that  is, /L applies only to the
1.1.1.4   misho     488:        expression on which it appears.
1.1.1.2   misho     489: 
1.1.1.5 ! misho     490:        The /M modifier causes the size in bytes of the memory  block  used  to
        !           491:        hold  the compiled pattern to be output. This does not include the size
        !           492:        of the pcre[16|32] block; it is just the actual compiled data.  If  the
1.1.1.4   misho     493:        pattern is successfully studied with the PCRE_STUDY_JIT_COMPILE option,
1.1.1.2   misho     494:        the size of the JIT compiled code is also output.
                    495: 
1.1.1.5 ! misho     496:        The /S modifier causes  pcre[16|32]_study()  to  be  called  after  the
        !           497:        expression  has been compiled, and the results used when the expression
1.1.1.4   misho     498:        is matched. There are a number of qualifying characters that may follow
                    499:        /S.  They may appear in any order.
                    500: 
1.1.1.5 ! misho     501:        If /S is followed by an exclamation mark, pcre[16|32]_study() is called
        !           502:        with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return  a
1.1.1.4   misho     503:        pcre_extra block, even when studying discovers no useful information.
                    504: 
                    505:        If /S is followed by a second S character, it suppresses studying, even
1.1.1.5 ! misho     506:        if it was requested externally by the  -s  command  line  option.  This
        !           507:        makes  it possible to specify that certain patterns are always studied,
1.1.1.4   misho     508:        and others are never studied, independently of -s. This feature is used
                    509:        in the test files in a few cases where the output is different when the
                    510:        pattern is studied.
                    511: 
1.1.1.5 ! misho     512:        If the  /S  modifier  is  followed  by  a  +  character,  the  call  to
        !           513:        pcre[16|32]_study()  is made with all the JIT study options, requesting
        !           514:        just-in-time optimization support if it is available, for  both  normal
        !           515:        and  partial matching. If you want to restrict the JIT compiling modes,
1.1.1.3   misho     516:        you can follow /S+ with a digit in the range 1 to 7:
                    517: 
                    518:          1  normal match only
                    519:          2  soft partial match only
                    520:          3  normal match and soft partial match
                    521:          4  hard partial match only
                    522:          6  soft and hard partial match
                    523:          7  all three modes (default)
                    524: 
                    525:        If /S++ is used instead of /S+ (with or without a following digit), the
1.1.1.5 ! misho     526:        text  "(JIT)"  is  added  to  the first output line after a match or no
1.1.1.3   misho     527:        match when JIT-compiled code was actually used.
                    528: 
1.1.1.5 ! misho     529:        Note that there is also an independent /+  modifier;  it  must  not  be
1.1.1.3   misho     530:        given immediately after /S or /S+ because this will be misinterpreted.
                    531: 
                    532:        If JIT studying is successful, the compiled JIT code will automatically
1.1.1.5 ! misho     533:        be used when pcre[16|32]_exec() is run, except when  incompatible  run-
        !           534:        time  options are specified. For more details, see the pcrejit documen-
        !           535:        tation. See also the \J escape sequence below for a way of setting  the
1.1.1.4   misho     536:        size of the JIT stack.
                    537: 
1.1.1.5 ! misho     538:        Finally,  if  /S  is  followed by a minus character, JIT compilation is
        !           539:        suppressed, even if it was requested externally by the -s command  line
        !           540:        option.  This makes it possible to specify that JIT is never to be used
1.1.1.4   misho     541:        for certain patterns.
1.1.1.2   misho     542: 
1.1.1.5 ! misho     543:        The /T modifier must be followed by a single digit. It  causes  a  spe-
1.1.1.4   misho     544:        cific set of built-in character tables to be passed to pcre[16|32]_com-
1.1.1.5 ! misho     545:        pile(). It is used in the standard PCRE tests to check  behaviour  with
1.1.1.2   misho     546:        different character tables. The digit specifies the tables as follows:
1.1       misho     547: 
                    548:          0   the default ASCII tables, as distributed in
                    549:                pcre_chartables.c.dist
                    550:          1   a set of tables defining ISO 8859 characters
                    551: 
1.1.1.5 ! misho     552:        In  table 1, some characters whose codes are greater than 128 are iden-
1.1       misho     553:        tified as letters, digits, spaces, etc.
                    554: 
                    555:    Using the POSIX wrapper API
                    556: 
1.1.1.5 ! misho     557:        The /P modifier causes pcretest to call PCRE via the POSIX wrapper  API
        !           558:        rather  than its native API. This supports only the 8-bit library. When
        !           559:        /P is set, the following modifiers set options for the regcomp()  func-
1.1.1.2   misho     560:        tion:
1.1       misho     561: 
                    562:          /i    REG_ICASE
                    563:          /m    REG_NEWLINE
                    564:          /N    REG_NOSUB
                    565:          /s    REG_DOTALL     )
                    566:          /U    REG_UNGREEDY   ) These options are not part of
                    567:          /W    REG_UCP        )   the POSIX standard
                    568:          /8    REG_UTF8       )
                    569: 
1.1.1.5 ! misho     570:        The  /+  modifier  works  as  described  above. All other modifiers are
1.1       misho     571:        ignored.
                    572: 
1.1.1.5 ! misho     573:    Locking out certain modifiers
        !           574: 
        !           575:        PCRE can be compiled with or without support for certain features  such
        !           576:        as  UTF-8/16/32  or Unicode properties. Accordingly, the standard tests
        !           577:        are split up into a number of different files  that  are  selected  for
        !           578:        running  depending  on  which features are available. When updating the
        !           579:        tests, it is all too easy to put a new test into the wrong file by mis-
        !           580:        take;  for example, to put a test that requires UTF support into a file
        !           581:        that is used when it is not available. To help detect such mistakes  as
        !           582:        early  as  possible, there is a facility for locking out specific modi-
        !           583:        fiers. If an input line for pcretest starts with the string "< forbid "
        !           584:        the  following  sequence  of characters is taken as a list of forbidden
        !           585:        modifiers. For example, in the test files that must not use UTF or Uni-
        !           586:        code property support, this line appears:
        !           587: 
        !           588:          < forbid 8W
        !           589: 
        !           590:        This  locks out the /8 and /W modifiers. An immediate error is given if
        !           591:        they are subsequently encountered. If the character string  contains  <
        !           592:        but  not  >,  all  the  multi-character modifiers that begin with < are
        !           593:        locked out. Otherwise, such modifiers must be  explicitly  listed,  for
        !           594:        example:
        !           595: 
        !           596:          < forbid <JS><cr>
        !           597: 
        !           598:        There must be a single space between < and "forbid" for this feature to
        !           599:        be recognised. If there is not, the line is  interpreted  either  as  a
        !           600:        request  to  re-load  a pre-compiled pattern (see "SAVING AND RELOADING
        !           601:        COMPILED PATTERNS" below) or, if there is a another < character,  as  a
        !           602:        pattern that uses < as its delimiter.
        !           603: 
1.1       misho     604: 
                    605: DATA LINES
                    606: 
1.1.1.4   misho     607:        Before  each  data  line  is  passed to pcre[16|32]_exec(), leading and
                    608:        trailing white space is removed, and it is then scanned for \  escapes.
                    609:        Some  of  these are pretty esoteric features, intended for checking out
                    610:        some of the more complicated features of PCRE. If you are just  testing
1.1.1.2   misho     611:        "ordinary"  regular  expressions, you probably don't need any of these.
                    612:        The following escapes are recognized:
1.1       misho     613: 
                    614:          \a         alarm (BEL, \x07)
                    615:          \b         backspace (\x08)
                    616:          \e         escape (\x27)
                    617:          \f         form feed (\x0c)
                    618:          \n         newline (\x0a)
                    619:          \qdd       set the PCRE_MATCH_LIMIT limit to dd
                    620:                       (any number of digits)
                    621:          \r         carriage return (\x0d)
                    622:          \t         tab (\x09)
                    623:          \v         vertical tab (\x0b)
1.1.1.2   misho     624:          \nnn       octal character (up to 3 octal digits); always
1.1.1.4   misho     625:                       a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode
1.1.1.5 ! misho     626:          \o{dd...}  octal character (any number of octal digits}
1.1       misho     627:          \xhh       hexadecimal byte (up to 2 hex digits)
1.1.1.2   misho     628:          \x{hh...}  hexadecimal character (any number of hex digits)
1.1.1.4   misho     629:          \A         pass the PCRE_ANCHORED option to pcre[16|32]_exec()
                    630:                       or pcre[16|32]_dfa_exec()
                    631:          \B         pass the PCRE_NOTBOL option to pcre[16|32]_exec()
                    632:                       or pcre[16|32]_dfa_exec()
                    633:          \Cdd       call pcre[16|32]_copy_substring() for substring dd
1.1       misho     634:                       after a successful match (number less than 32)
1.1.1.4   misho     635:          \Cname     call pcre[16|32]_copy_named_substring() for substring
1.1       misho     636:                       "name" after a successful match (name termin-
                    637:                       ated by next non alphanumeric character)
                    638:          \C+        show the current captured substrings at callout
                    639:                       time
                    640:          \C-        do not supply a callout function
                    641:          \C!n       return 1 instead of 0 when callout number n is
                    642:                       reached
                    643:          \C!n!m     return 1 instead of 0 when callout number n is
                    644:                       reached for the nth time
                    645:          \C*n       pass the number n (may be negative) as callout
                    646:                       data; this is used as the callout return value
1.1.1.4   misho     647:          \D         use the pcre[16|32]_dfa_exec() match function
                    648:          \F         only shortest match for pcre[16|32]_dfa_exec()
                    649:          \Gdd       call pcre[16|32]_get_substring() for substring dd
1.1       misho     650:                       after a successful match (number less than 32)
1.1.1.4   misho     651:          \Gname     call pcre[16|32]_get_named_substring() for substring
1.1       misho     652:                       "name" after a successful match (name termin-
                    653:                       ated by next non-alphanumeric character)
                    654:          \Jdd       set up a JIT stack of dd kilobytes maximum (any
                    655:                       number of digits)
1.1.1.4   misho     656:          \L         call pcre[16|32]_get_substringlist() after a
1.1       misho     657:                       successful match
                    658:          \M         discover the minimum MATCH_LIMIT and
                    659:                       MATCH_LIMIT_RECURSION settings
1.1.1.4   misho     660:          \N         pass the PCRE_NOTEMPTY option to pcre[16|32]_exec()
                    661:                       or pcre[16|32]_dfa_exec(); if used twice, pass the
1.1       misho     662:                       PCRE_NOTEMPTY_ATSTART option
                    663:          \Odd       set the size of the output vector passed to
1.1.1.4   misho     664:                       pcre[16|32]_exec() to dd (any number of digits)
                    665:          \P         pass the PCRE_PARTIAL_SOFT option to pcre[16|32]_exec()
                    666:                       or pcre[16|32]_dfa_exec(); if used twice, pass the
1.1       misho     667:                       PCRE_PARTIAL_HARD option
                    668:          \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
                    669:                       (any number of digits)
1.1.1.4   misho     670:          \R         pass the PCRE_DFA_RESTART option to pcre[16|32]_dfa_exec()
1.1       misho     671:          \S         output details of memory get/free calls during matching
1.1.1.4   misho     672:          \Y            pass    the    PCRE_NO_START_OPTIMIZE     option     to
                    673:        pcre[16|32]_exec()
                    674:                       or pcre[16|32]_dfa_exec()
                    675:          \Z         pass the PCRE_NOTEOL option to pcre[16|32]_exec()
                    676:                       or pcre[16|32]_dfa_exec()
                    677:          \?         pass the PCRE_NO_UTF[8|16|32]_CHECK option to
                    678:                       pcre[16|32]_exec() or pcre[16|32]_dfa_exec()
1.1       misho     679:          \>dd       start the match at offset dd (optional "-"; then
                    680:                       any number of digits); this sets the startoffset
1.1.1.4   misho     681:                       argument         for        pcre[16|32]_exec()        or
                    682:        pcre[16|32]_dfa_exec()
                    683:          \<cr>      pass the PCRE_NEWLINE_CR option to pcre[16|32]_exec()
                    684:                       or pcre[16|32]_dfa_exec()
                    685:          \<lf>      pass the PCRE_NEWLINE_LF option to pcre[16|32]_exec()
                    686:                       or pcre[16|32]_dfa_exec()
                    687:          \<crlf>    pass the PCRE_NEWLINE_CRLF option to pcre[16|32]_exec()
                    688:                       or pcre[16|32]_dfa_exec()
                    689:          \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre[16|32]_exec()
                    690:                       or pcre[16|32]_dfa_exec()
                    691:          \<any>     pass the PCRE_NEWLINE_ANY option to pcre[16|32]_exec()
                    692:                       or pcre[16|32]_dfa_exec()
1.1.1.2   misho     693: 
                    694:        The use of \x{hh...} is not dependent on the use of the /8 modifier  on
                    695:        the  pattern. It is recognized always. There may be any number of hexa-
                    696:        decimal digits inside the braces; invalid  values  provoke  error  mes-
                    697:        sages.
                    698: 
                    699:        Note  that  \xhh  specifies one byte rather than one character in UTF-8
                    700:        mode; this makes it possible to construct invalid UTF-8  sequences  for
                    701:        testing  purposes.  On the other hand, \x{hh} is interpreted as a UTF-8
                    702:        character in UTF-8 mode, generating more than one byte if the value  is
                    703:        greater  than  127.   When testing the 8-bit library not in UTF-8 mode,
                    704:        \x{hh} generates one byte for values less than 256, and causes an error
                    705:        for greater values.
                    706: 
                    707:        In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
                    708:        possible to construct invalid UTF-16 sequences for testing purposes.
1.1       misho     709: 
1.1.1.4   misho     710:        In UTF-32 mode, all 4- to 8-digit \x{...}  values  are  accepted.  This
                    711:        makes  it  possible  to  construct invalid UTF-32 sequences for testing
                    712:        purposes.
                    713: 
1.1.1.2   misho     714:        The escapes that specify line ending  sequences  are  literal  strings,
1.1       misho     715:        exactly as shown. No more than one newline setting should be present in
                    716:        any data line.
                    717: 
1.1.1.2   misho     718:        A backslash followed by anything else just escapes the  anything  else.
                    719:        If  the very last character is a backslash, it is ignored. This gives a
                    720:        way of passing an empty line as data, since a real  empty  line  termi-
1.1       misho     721:        nates the data input.
                    722: 
1.1.1.2   misho     723:        The  \J escape provides a way of setting the maximum stack size that is
                    724:        used by the just-in-time optimization code. It is ignored if JIT  opti-
                    725:        mization  is  not being used. Providing a stack that is larger than the
1.1       misho     726:        default 32K is necessary only for very complicated patterns.
                    727: 
1.1.1.4   misho     728:        If \M is present, pcretest calls pcre[16|32]_exec() several times, with
1.1.1.2   misho     729:        different values in the match_limit and match_limit_recursion fields of
1.1.1.4   misho     730:        the pcre[16|32]_extra data structure, until it finds the  minimum  num-
                    731:        bers for each parameter that allow pcre[16|32]_exec() to complete with-
                    732:        out error. Because this is testing a specific  feature  of  the  normal
                    733:        interpretive pcre[16|32]_exec() execution, the use of any JIT optimiza-
                    734:        tion that might have been set up by the /S+ qualifier of -s+ option  is
                    735:        disabled.
                    736: 
                    737:        The  match_limit number is a measure of the amount of backtracking that
                    738:        takes place, and checking it out can be instructive.  For  most  simple
                    739:        matches,  the  number  is quite small, but for patterns with very large
                    740:        numbers of matching possibilities, it can  become  large  very  quickly
                    741:        with  increasing  length  of  subject string. The match_limit_recursion
                    742:        number is a measure of how much stack (or, if  PCRE  is  compiled  with
                    743:        NO_RECURSE,  how  much  heap)  memory  is  needed to complete the match
1.1       misho     744:        attempt.
                    745: 
1.1.1.4   misho     746:        When \O is used, the value specified may be higher or  lower  than  the
1.1       misho     747:        size set by the -O command line option (or defaulted to 45); \O applies
1.1.1.4   misho     748:        only to the call  of  pcre[16|32]_exec()  for  the  line  in  which  it
                    749:        appears.
1.1       misho     750: 
1.1.1.2   misho     751:        If  the /P modifier was present on the pattern, causing the POSIX wrap-
                    752:        per API to be used, the only option-setting  sequences  that  have  any
                    753:        effect  are  \B,  \N,  and  \Z,  causing  REG_NOTBOL, REG_NOTEMPTY, and
1.1       misho     754:        REG_NOTEOL, respectively, to be passed to regexec().
                    755: 
                    756: 
                    757: THE ALTERNATIVE MATCHING FUNCTION
                    758: 
                    759:        By  default,  pcretest  uses  the  standard  PCRE  matching   function,
1.1.1.4   misho     760:        pcre[16|32]_exec()  to  match  each  data  line.  PCRE also supports an
                    761:        alternative matching function, pcre[16|32]_dfa_test(),  which  operates
                    762:        in  a different way, and has some restrictions. The differences between
                    763:        the two functions are described in the pcrematching documentation.
1.1       misho     764: 
                    765:        If a data line contains the \D escape sequence, or if the command  line
1.1.1.2   misho     766:        contains  the  -dfa  option, the alternative matching function is used.
1.1       misho     767:        This function finds all possible matches at a given point. If, however,
                    768:        the  \F escape sequence is present in the data line, it stops after the
                    769:        first match is found. This is always the shortest possible match.
                    770: 
                    771: 
                    772: DEFAULT OUTPUT FROM PCRETEST
                    773: 
                    774:        This section describes the output when the  normal  matching  function,
1.1.1.4   misho     775:        pcre[16|32]_exec(), is being used.
1.1       misho     776: 
                    777:        When a match succeeds, pcretest outputs the list of captured substrings
1.1.1.4   misho     778:        that pcre[16|32]_exec() returns, starting with number 0 for the  string
1.1.1.2   misho     779:        that  matched  the whole pattern. Otherwise, it outputs "No match" when
                    780:        the return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by  the
1.1.1.4   misho     781:        partially    matching   substring   when   pcre[16|32]_exec()   returns
1.1.1.2   misho     782:        PCRE_ERROR_PARTIAL. (Note that this is the entire  substring  that  was
                    783:        inspected  during  the  partial match; it may include characters before
                    784:        the actual match start if a lookbehind assertion, \K,  \b,  or  \B  was
                    785:        involved.)  For  any  other  return, pcretest outputs the PCRE negative
                    786:        error number and a short descriptive phrase. If the error is  a  failed
                    787:        UTF  string check, the offset of the start of the failing character and
                    788:        the reason code are also output, provided that the size of  the  output
                    789:        vector  is  at least two. Here is an example of an interactive pcretest
                    790:        run.
1.1       misho     791: 
                    792:          $ pcretest
                    793:          PCRE version 8.13 2011-04-30
                    794: 
                    795:            re> /^abc(\d+)/
                    796:          data> abc123
                    797:           0: abc123
                    798:           1: 123
                    799:          data> xyz
                    800:          No match
                    801: 
                    802:        Unset capturing substrings that are not followed by one that is set are
1.1.1.4   misho     803:        not  returned  by pcre[16|32]_exec(), and are not shown by pcretest. In
                    804:        the following example, there are two capturing substrings, but when the
1.1.1.2   misho     805:        first  data  line is matched, the second, unset substring is not shown.
                    806:        An "internal" unset substring is shown as "<unset>", as for the  second
1.1       misho     807:        data line.
                    808: 
                    809:            re> /(a)|(b)/
                    810:          data> a
                    811:           0: a
                    812:           1: a
                    813:          data> b
                    814:           0: b
                    815:           1: <unset>
                    816:           2: b
                    817: 
1.1.1.2   misho     818:        If  the strings contain any non-printing characters, they are output as
                    819:        \xhh escapes if the value is less than 256 and UTF  mode  is  not  set.
                    820:        Otherwise they are output as \x{hh...} escapes. See below for the defi-
                    821:        nition of non-printing characters. If the pattern has the /+  modifier,
                    822:        the  output  for substring 0 is followed by the the rest of the subject
                    823:        string, identified by "0+" like this:
1.1       misho     824: 
                    825:            re> /cat/+
                    826:          data> cataract
                    827:           0: cat
                    828:           0+ aract
                    829: 
1.1.1.2   misho     830:        If the pattern has the /g or /G modifier,  the  results  of  successive
1.1       misho     831:        matching attempts are output in sequence, like this:
                    832: 
                    833:            re> /\Bi(\w\w)/g
                    834:          data> Mississippi
                    835:           0: iss
                    836:           1: ss
                    837:           0: iss
                    838:           1: ss
                    839:           0: ipp
                    840:           1: pp
                    841: 
1.1.1.2   misho     842:        "No  match" is output only if the first match attempt fails. Here is an
                    843:        example of a failure message (the offset 4 that is specified by \>4  is
1.1       misho     844:        past the end of the subject string):
                    845: 
                    846:            re> /xyz/
                    847:          data> xyz\>4
                    848:          Error -24 (bad offset value)
                    849: 
1.1.1.2   misho     850:        If  any  of the sequences \C, \G, or \L are present in a data line that
                    851:        is successfully matched, the substrings extracted  by  the  convenience
1.1       misho     852:        functions are output with C, G, or L after the string number instead of
                    853:        a colon. This is in addition to the normal full list. The string length
1.1.1.2   misho     854:        (that  is,  the return from the extraction function) is given in paren-
1.1       misho     855:        theses after each string for \C and \G.
                    856: 
                    857:        Note that whereas patterns can be continued over several lines (a plain
                    858:        ">" prompt is used for continuations), data lines may not. However new-
1.1.1.2   misho     859:        lines can be included in data by means of the \n escape (or  \r,  \r\n,
1.1       misho     860:        etc., depending on the newline sequence setting).
                    861: 
                    862: 
                    863: OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
                    864: 
1.1.1.4   misho     865:        When the alternative matching function, pcre[16|32]_dfa_exec(), is used
1.1.1.2   misho     866:        (by means of the \D escape sequence or the -dfa command  line  option),
                    867:        the  output  consists  of  a  list of all the matches that start at the
                    868:        first point in the subject where there is at least one match. For exam-
                    869:        ple:
1.1       misho     870: 
                    871:            re> /(tang|tangerine|tan)/
                    872:          data> yellow tangerine\D
                    873:           0: tangerine
                    874:           1: tang
                    875:           2: tan
                    876: 
                    877:        (Using  the  normal  matching function on this data finds only "tang".)
                    878:        The longest matching string is always given first (and numbered  zero).
                    879:        After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
                    880:        lowed by the partially matching  substring.  (Note  that  this  is  the
                    881:        entire  substring  that  was inspected during the partial match; it may
                    882:        include characters before the actual match start if a lookbehind asser-
                    883:        tion, \K, \b, or \B was involved.)
                    884: 
                    885:        If /g is present on the pattern, the search for further matches resumes
                    886:        at the end of the longest match. For example:
                    887: 
                    888:            re> /(tang|tangerine|tan)/g
                    889:          data> yellow tangerine and tangy sultana\D
                    890:           0: tangerine
                    891:           1: tang
                    892:           2: tan
                    893:           0: tang
                    894:           1: tan
                    895:           0: tan
                    896: 
                    897:        Since the matching function does not  support  substring  capture,  the
                    898:        escape  sequences  that  are concerned with captured substrings are not
                    899:        relevant.
                    900: 
                    901: 
                    902: RESTARTING AFTER A PARTIAL MATCH
                    903: 
                    904:        When the alternative matching function has given the PCRE_ERROR_PARTIAL
                    905:        return,  indicating that the subject partially matched the pattern, you
                    906:        can restart the match with additional subject data by means of  the  \R
                    907:        escape sequence. For example:
                    908: 
                    909:            re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
                    910:          data> 23ja\P\D
                    911:          Partial match: 23ja
                    912:          data> n05\R\D
                    913:           0: n05
                    914: 
                    915:        For  further  information  about  partial matching, see the pcrepartial
                    916:        documentation.
                    917: 
                    918: 
                    919: CALLOUTS
                    920: 
                    921:        If the pattern contains any callout requests, pcretest's callout  func-
                    922:        tion  is  called  during  matching. This works with both matching func-
                    923:        tions. By default, the called function displays the callout number, the
                    924:        start  and  current  positions in the text at the callout time, and the
1.1.1.2   misho     925:        next pattern item to be tested. For example:
1.1       misho     926: 
                    927:          --->pqrabcdef
                    928:            0    ^  ^     \d
                    929: 
1.1.1.2   misho     930:        This output indicates that  callout  number  0  occurred  for  a  match
                    931:        attempt  starting  at  the fourth character of the subject string, when
                    932:        the pointer was at the seventh character of the data, and when the next
                    933:        pattern  item  was  \d.  Just one circumflex is output if the start and
                    934:        current positions are the same.
1.1       misho     935: 
                    936:        Callouts numbered 255 are assumed to be automatic callouts, inserted as
                    937:        a  result  of the /C pattern modifier. In this case, instead of showing
                    938:        the callout number, the offset in the pattern, preceded by a  plus,  is
                    939:        output. For example:
                    940: 
                    941:            re> /\d?[A-E]\*/C
                    942:          data> E*
                    943:          --->E*
                    944:           +0 ^      \d?
                    945:           +3 ^      [A-E]
                    946:           +8 ^^     \*
                    947:          +10 ^ ^
                    948:           0: E*
                    949: 
                    950:        If a pattern contains (*MARK) items, an additional line is output when-
                    951:        ever a change of latest mark is passed to  the  callout  function.  For
                    952:        example:
                    953: 
                    954:            re> /a(*MARK:X)bc/C
                    955:          data> abc
                    956:          --->abc
                    957:           +0 ^       a
                    958:           +1 ^^      (*MARK:X)
                    959:          +10 ^^      b
                    960:          Latest Mark: X
                    961:          +11 ^ ^     c
                    962:          +12 ^  ^
                    963:           0: abc
                    964: 
                    965:        The  mark  changes between matching "a" and "b", but stays the same for
                    966:        the rest of the match, so nothing more is output. If, as  a  result  of
                    967:        backtracking,  the  mark  reverts to being unset, the text "<unset>" is
                    968:        output.
                    969: 
                    970:        The callout function in pcretest returns zero (carry  on  matching)  by
                    971:        default,  but you can use a \C item in a data line (as described above)
                    972:        to change this and other parameters of the callout.
                    973: 
                    974:        Inserting callouts can be helpful when using pcretest to check  compli-
                    975:        cated  regular expressions. For further information about callouts, see
                    976:        the pcrecallout documentation.
                    977: 
                    978: 
                    979: NON-PRINTING CHARACTERS
                    980: 
                    981:        When pcretest is outputting text in the compiled version of a  pattern,
                    982:        bytes  other  than 32-126 are always treated as non-printing characters
                    983:        are are therefore shown as hex escapes.
                    984: 
                    985:        When pcretest is outputting text that is a matched part  of  a  subject
                    986:        string,  it behaves in the same way, unless a different locale has been
                    987:        set for the  pattern  (using  the  /L  modifier).  In  this  case,  the
                    988:        isprint() function to distinguish printing and non-printing characters.
                    989: 
                    990: 
                    991: SAVING AND RELOADING COMPILED PATTERNS
                    992: 
                    993:        The  facilities  described  in  this section are not available when the
                    994:        POSIX interface to PCRE is being used, that is,  when  the  /P  pattern
                    995:        modifier is specified.
                    996: 
                    997:        When the POSIX interface is not in use, you can cause pcretest to write
                    998:        a compiled pattern to a file, by following the modifiers with >  and  a
                    999:        file name.  For example:
                   1000: 
                   1001:          /pattern/im >/some/file
                   1002: 
                   1003:        See  the pcreprecompile documentation for a discussion about saving and
                   1004:        re-using compiled patterns.  Note that if the pattern was  successfully
                   1005:        studied with JIT optimization, the JIT data cannot be saved.
                   1006: 
                   1007:        The  data  that  is  written  is  binary. The first eight bytes are the
                   1008:        length of the compiled pattern data  followed  by  the  length  of  the
                   1009:        optional  study  data,  each  written as four bytes in big-endian order
                   1010:        (most significant byte first). If there is no study  data  (either  the
                   1011:        pattern was not studied, or studying did not return any data), the sec-
                   1012:        ond length is zero. The lengths are followed by an exact  copy  of  the
                   1013:        compiled  pattern.  If  there is additional study data, this (excluding
                   1014:        any JIT data) follows immediately after  the  compiled  pattern.  After
                   1015:        writing the file, pcretest expects to read a new pattern.
                   1016: 
                   1017:        A  saved  pattern  can  be reloaded into pcretest by specifying < and a
1.1.1.5 ! misho    1018:        file name instead of a pattern. There must be no space  between  <  and
        !          1019:        the  file  name,  which  must  not  contain a < character, as otherwise
        !          1020:        pcretest will interpret the line as a pattern delimited  by  <  charac-
        !          1021:        ters. For example:
1.1       misho    1022: 
                   1023:           re> </some/file
                   1024:          Compiled pattern loaded from /some/file
                   1025:          No study data
                   1026: 
1.1.1.5 ! misho    1027:        If  the  pattern  was previously studied with the JIT optimization, the
        !          1028:        JIT information cannot be saved and restored, and so is lost. When  the
        !          1029:        pattern  has  been  loaded, pcretest proceeds to read data lines in the
1.1       misho    1030:        usual way.
                   1031: 
1.1.1.5 ! misho    1032:        You can copy a file written by pcretest to a different host and  reload
        !          1033:        it  there,  even  if the new host has opposite endianness to the one on
        !          1034:        which the pattern was compiled. For example, you can compile on an  i86
        !          1035:        machine  and  run  on  a SPARC machine. When a pattern is reloaded on a
1.1.1.2   misho    1036:        host with different endianness, the confirmation message is changed to:
                   1037: 
                   1038:          Compiled pattern (byte-inverted) loaded from /some/file
                   1039: 
                   1040:        The test suite contains some saved pre-compiled patterns with different
1.1.1.5 ! misho    1041:        endianness.  These  are  reloaded  using "<!" instead of just "<". This
1.1.1.2   misho    1042:        suppresses the "(byte-inverted)" text so that the output is the same on
1.1.1.5 ! misho    1043:        all  hosts.  It  also forces debugging output once the pattern has been
1.1.1.2   misho    1044:        reloaded.
1.1       misho    1045: 
1.1.1.5 ! misho    1046:        File names for saving and reloading can be absolute  or  relative,  but
        !          1047:        note  that the shell facility of expanding a file name that starts with
1.1       misho    1048:        a tilde (~) is not available.
                   1049: 
1.1.1.5 ! misho    1050:        The ability to save and reload files in pcretest is intended for  test-
        !          1051:        ing  and experimentation. It is not intended for production use because
        !          1052:        only a single pattern can be written to a file. Furthermore,  there  is
        !          1053:        no  facility  for  supplying  custom  character  tables  for use with a
        !          1054:        reloaded pattern. If the original  pattern  was  compiled  with  custom
        !          1055:        tables,  an  attempt to match a subject string using a reloaded pattern
        !          1056:        is likely to cause pcretest to crash.  Finally, if you attempt to  load
1.1       misho    1057:        a file that is not in the correct format, the result is undefined.
                   1058: 
                   1059: 
                   1060: SEE ALSO
                   1061: 
1.1.1.5 ! misho    1062:        pcre(3),  pcre16(3),  pcre32(3),  pcreapi(3),  pcrecallout(3), pcrejit,
1.1.1.4   misho    1063:        pcrematching(3), pcrepartial(d), pcrepattern(3), pcreprecompile(3).
1.1       misho    1064: 
                   1065: 
                   1066: AUTHOR
                   1067: 
                   1068:        Philip Hazel
                   1069:        University Computing Service
                   1070:        Cambridge CB2 3QH, England.
                   1071: 
                   1072: 
                   1073: REVISION
                   1074: 
1.1.1.5 ! misho    1075:        Last updated: 12 November 2013
1.1.1.4   misho    1076:        Copyright (c) 1997-2013 University of Cambridge.

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