Add /noupdate as a ratelimit option.

[users/heiko/exim.git] / doc / doc-txt / pcretest.txt

diff --git a/doc/doc-txt/pcretest.txt b/doc/doc-txt/pcretest.txt
index 9e9b70ef4b0af06f42225bcc22dc898fc10aad28..1a0424c20161dc08d8568f2888f3504cce773455 100644 (file)
--- a/doc/doc-txt/pcretest.txt
+++ b/doc/doc-txt/pcretest.txt
@@ -1,19 +1,18 @@
-This file contains the PCRE man page that described the pcretest program. Note 
-that not all of the features of PCRE are available in the limited version that 
+This file contains the PCRE man page that described the pcretest program. Note
+that not all of the features of PCRE are available in the limited version that

 is built with Exim.
 -------------------------------------------------------------------------------
 
 PCRETEST(1)                                                        PCRETEST(1)
 
 
 is built with Exim.
 -------------------------------------------------------------------------------
 
 PCRETEST(1)                                                        PCRETEST(1)
 
 

-

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

+

 SYNOPSIS
 
 SYNOPSIS
 

-       pcretest [-C] [-d] [-i] [-m] [-o osize] [-p] [-t] [source]
-            [destination]
+       pcretest [options] [source] [destination]

 
        pcretest  was written as a test program for the PCRE regular expression
        library itself, but it can also be used for experimenting with  regular
 
        pcretest  was written as a test program for the PCRE regular expression
        library itself, but it can also be used for experimenting with  regular


@@ -25,99 +24,126 @@ SYNOPSIS
 
 OPTIONS
 
 
 OPTIONS
 

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

        -C        Output the version number of the PCRE library, and all avail-
        -C        Output the version number of the PCRE library, and all avail-

-                 able   information  about  the  optional  features  that  are
+                 able  information  about  the  optional  features  that   are

                  included, and then exit.
 
                  included, and then exit.
 

-       -d        Behave as if each regex had  the  /D  (debug)  modifier;  the
-                 internal form is output after compilation.
+       -d        Behave  as  if  each  regex  has the /D (debug) modifier; the
+                 internal form and information about the compiled  pattern  is
+                 output after compilation; -d is equivalent to -b -i.
+
+       -dfa      Behave  as if each data line contains the \D escape sequence;
+                 this    causes    the    alternative    matching    function,
+                 pcre_dfa_exec(),   to   be   used  instead  of  the  standard
+                 pcre_exec() function (more detail is given below).
+
+       -help     Output a brief summary these options and then exit.

 
 

-       -i        Behave  as  if  each  regex  had the /I modifier; information
+       -i        Behave as if each regex  has  the  /I  modifier;  information

                  about the compiled pattern is given after compilation.
 
                  about the compiled pattern is given after compilation.
 

-       -m        Output the size of each compiled pattern after  it  has  been
-                 compiled.  This  is  equivalent  to adding /M to each regular
-                 expression.  For  compatibility  with  earlier  versions   of
+       -m        Output  the  size  of each compiled pattern after it has been
+                 compiled. This is equivalent to adding  /M  to  each  regular
+                 expression.   For  compatibility  with  earlier  versions  of

                  pcretest, -s is a synonym for -m.
 
                  pcretest, -s is a synonym for -m.
 

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

 
 

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

 
 

-       -t        Run  each  compile, study, and match many times with a timer,
-                 and output resulting time per compile or match (in  millisec-
-                 onds).  Do  not set -m with -t, because you will then get the
-                 size output a zillion times, and  the  timing  will  be  dis-
-                 torted.
+       -q        Do not output the version number of pcretest at the start  of
+                 execution.
+
+       -S size   On  Unix-like  systems,  set the size of the runtime stack to
+                 size megabytes.
+
+       -t        Run each compile, study, and match many times with  a  timer,
+                 and  output resulting time per compile or match (in millisec-
+                 onds). Do not set -m with -t, because you will then  get  the
+                 size  output  a  zillion  times,  and the timing will be dis-
+                 torted. You can control the number  of  iterations  that  are
+                 used  for timing by following -t with a number (as a separate
+                 item on the command line). For example, "-t 1000" would iter-
+                 ate 1000 times. The default is to iterate 500000 times.
+
+       -tm       This is like -t except that it times only the matching phase,
+                 not the compile or study phases.

 
 
 DESCRIPTION
 
 
 
 DESCRIPTION
 

-       If  pcretest  is  given two filename arguments, it reads from the first
+       If pcretest is given two filename arguments, it reads  from  the  first

        and writes to the second. If it is given only one filename argument, it
        and writes to the second. If it is given only one filename argument, it

-       reads  from  that  file  and writes to stdout. Otherwise, it reads from
-       stdin and writes to stdout, and prompts for each line of  input,  using
+       reads from that file and writes to stdout.  Otherwise,  it  reads  from
+       stdin  and  writes to stdout, and prompts for each line of input, using

        "re>" to prompt for regular expressions, and "data>" to prompt for data
        lines.
 
        The program handles any number of sets of input on a single input file.
        "re>" to prompt for regular expressions, and "data>" to prompt for data
        lines.
 
        The program handles any number of sets of input on a single input file.

-       Each  set starts with a regular expression, and continues with any num-
+       Each set starts with a regular expression, and continues with any  num-

        ber of data lines to be matched against the pattern.
 
        ber of data lines to be matched against the pattern.
 

-       Each data line is matched separately and independently. If you want  to
-       do  multiple-line  matches, you have to use the \n escape sequence in a
-       single line of input to encode  the  newline  characters.  The  maximum
-       length of data line is 30,000 characters.
+       Each  data line is matched separately and independently. If you want to
+       do multi-line matches, you have to use the \n escape sequence (or \r or
+       \r\n, etc., depending on the newline setting) in a single line of input
+       to encode the newline sequences. There is no limit  on  the  length  of
+       data  lines;  the  input  buffer is automatically extended if it is too
+       small.

 
 

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

 
          /(a|bc)x+yz/
 
 
          /(a|bc)x+yz/
 

-       White  space before the initial delimiter is ignored. A regular expres-
-       sion may be continued over several input lines, in which case the  new-
-       line  characters  are included within it. It is possible to include the
+       White space before the initial delimiter is ignored. A regular  expres-
+       sion  may be continued over several input lines, in which case the new-
+       line characters are included within it. It is possible to  include  the

        delimiter within the pattern by escaping it, for example
 
          /abc\/def/
 
        delimiter within the pattern by escaping it, for example
 
          /abc\/def/
 

-       If you do so, the escape and the delimiter form part  of  the  pattern,
-       but  since delimiters are always non-alphanumeric, this does not affect
-       its interpretation.  If the terminating delimiter is  immediately  fol-
+       If  you  do  so, the escape and the delimiter form part of the pattern,
+       but since delimiters are always non-alphanumeric, this does not  affect
+       its  interpretation.   If the terminating delimiter is immediately fol-

        lowed by a backslash, for example,
 
          /abc/\
 
        lowed by a backslash, for example,
 
          /abc/\
 

-       then  a  backslash  is added to the end of the pattern. This is done to
-       provide a way of testing the error condition that arises if  a  pattern
+       then a backslash is added to the end of the pattern. This  is  done  to
+       provide  a  way of testing the error condition that arises if a pattern

        finishes with a backslash, because
 
          /abc\/
 
        finishes with a backslash, because
 
          /abc\/
 

-       is  interpreted as the first line of a pattern that starts with "abc/",
+       is interpreted as the first line of a pattern that starts with  "abc/",

        causing pcretest to read the next line as a continuation of the regular
        expression.
 
 
 PATTERN MODIFIERS
 
        causing pcretest to read the next line as a continuation of the regular
        expression.
 
 
 PATTERN MODIFIERS
 

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

        and the first modifier, and between the modifiers themselves.
 
        The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
        and the first modifier, and between the modifiers themselves.
 
        The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,

-       PCRE_DOTALL,  or  PCRE_EXTENDED  options,  respectively, when pcre_com-
-       pile() is called. These four modifier letters have the same  effect  as
+       PCRE_DOTALL, or PCRE_EXTENDED  options,  respectively,  when  pcre_com-
+       pile()  is  called. These four modifier letters have the same effect as

        they do in Perl. For example:
 
          /caseless/i
        they do in Perl. For example:
 
          /caseless/i


@@ -125,12 +151,29 @@ PATTERN MODIFIERS
        The following table shows additional modifiers for setting PCRE options
        that do not correspond to anything in Perl:
 
        The following table shows additional modifiers for setting PCRE options
        that do not correspond to anything in Perl:
 

-         /A    PCRE_ANCHORED
-         /C    PCRE_AUTO_CALLOUT
-         /E    PCRE_DOLLAR_ENDONLY
-         /N    PCRE_NO_AUTO_CAPTURE
-         /U    PCRE_UNGREEDY
-         /X    PCRE_EXTRA
+         /A       PCRE_ANCHORED
+         /C       PCRE_AUTO_CALLOUT
+         /E       PCRE_DOLLAR_ENDONLY
+         /f       PCRE_FIRSTLINE
+         /J       PCRE_DUPNAMES
+         /N       PCRE_NO_AUTO_CAPTURE
+         /U       PCRE_UNGREEDY
+         /X       PCRE_EXTRA
+         /<cr>    PCRE_NEWLINE_CR
+         /<lf>    PCRE_NEWLINE_LF
+         /<crlf>  PCRE_NEWLINE_CRLF
+         /<any>   PCRE_NEWLINE_ANY
+
+       Those  specifying  line ending sequencess are literal strings as shown.
+       This example sets multiline matching  with  CRLF  as  the  line  ending
+       sequence:
+
+         /^abc/m<crlf>
+
+       Details  of the meanings of these PCRE options are given in the pcreapi
+       documentation.
+
+   Finding all matches in a string

 
        Searching for all possible matches within each subject  string  can  be
        requested  by  the  /g  or  /G modifier. After finding a match, PCRE is
 
        Searching for all possible matches within each subject  string  can  be
        requested  by  the  /g  or  /G modifier. After finding a match, PCRE is


@@ -149,6 +192,8 @@ PATTERN MODIFIERS
        one, and the normal match is retried. This imitates the way  Perl  han-
        dles such cases when using the /g modifier or the split() function.
 
        one, and the normal match is retried. This imitates the way  Perl  han-
        dles such cases when using the /g modifier or the split() function.
 

+   Other modifiers
+

        There are yet more modifiers for controlling the way pcretest operates.
 
        The /+ modifier requests that as well as outputting the substring  that
        There are yet more modifiers for controlling the way pcretest operates.
 
        The /+ modifier requests that as well as outputting the substring  that


@@ -156,83 +201,88 @@ PATTERN MODIFIERS
        remainder of the subject string. This is useful  for  tests  where  the
        subject contains multiple copies of the same substring.
 
        remainder of the subject string. This is useful  for  tests  where  the
        subject contains multiple copies of the same substring.
 

-       The  /L modifier must be followed directly by the name of a locale, for
+       The  /B modifier is a debugging feature. It requests that pcretest out-
+       put a representation of the compiled byte code after compilation.
+
+       The /L modifier must be followed directly by the name of a locale,  for

        example,
 
          /pattern/Lfr_FR
 
        For this reason, it must be the last modifier. The given locale is set,
        example,
 
          /pattern/Lfr_FR
 
        For this reason, it must be the last modifier. The given locale is set,

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

        appears.
 
        appears.
 

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

        put.
 
        put.
 

-       The /D modifier is a PCRE debugging feature, which also assumes /I.  It
-       causes the internal form of compiled regular expressions to  be  output
-       after compilation. If the pattern was studied, the information returned
-       is also output.
+       The /D modifier is a PCRE debugging feature, and is equivalent to  /BI,
+       that is, both the /B and the /I modifiers.

 
        The /F modifier causes pcretest to flip the byte order of the fields in
 
        The /F modifier causes pcretest to flip the byte order of the fields in

-       the  compiled  pattern  that  contain  2-byte  and 4-byte numbers. This
-       facility is for testing the feature in PCRE that allows it  to  execute
+       the compiled pattern that  contain  2-byte  and  4-byte  numbers.  This
+       facility  is  for testing the feature in PCRE that allows it to execute

        patterns that were compiled on a host with a different endianness. This
        patterns that were compiled on a host with a different endianness. This

-       feature is not available when the POSIX  interface  to  PCRE  is  being
-       used,  that is, when the /P pattern modifier is specified. See also the
+       feature  is  not  available  when  the POSIX interface to PCRE is being
+       used, that is, when the /P pattern modifier is specified. See also  the

        section about saving and reloading compiled patterns below.
 
        section about saving and reloading compiled patterns below.
 

-       The /S modifier causes pcre_study() to be called after  the  expression
+       The  /S  modifier causes pcre_study() to be called after the expression

        has been compiled, and the results used when the expression is matched.
 
        has been compiled, and the results used when the expression is matched.
 

-       The /M modifier causes the size of memory block used to hold  the  com-
+       The  /M  modifier causes the size of memory block used to hold the com-

        piled pattern to be output.
 
        piled pattern to be output.
 

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

 
 

-       The /8 modifier causes pcretest to call PCRE with the PCRE_UTF8  option
-       set.  This  turns on support for UTF-8 character handling in PCRE, pro-
-       vided that it was compiled with this  support  enabled.  This  modifier
+       The  /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option
+       set. This turns on support for UTF-8 character handling in  PCRE,  pro-
+       vided  that  it  was  compiled with this support enabled. This modifier

        also causes any non-printing characters in output strings to be printed
        using the \x{hh...} notation if they are valid UTF-8 sequences.
 
        also causes any non-printing characters in output strings to be printed
        using the \x{hh...} notation if they are valid UTF-8 sequences.
 

-       If the /? modifier  is  used  with  /8,  it  causes  pcretest  to  call
-       pcre_compile()  with  the  PCRE_NO_UTF8_CHECK  option,  to suppress the
+       If  the  /?  modifier  is  used  with  /8,  it  causes pcretest to call
+       pcre_compile() with the  PCRE_NO_UTF8_CHECK  option,  to  suppress  the

        checking of the string for UTF-8 validity.
 
 
 DATA LINES
 
        checking of the string for UTF-8 validity.
 
 
 DATA LINES
 

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

        following escapes are recognized:
 
        following escapes are recognized:
 

-         \a         alarm (= BEL)
-         \b         backspace
-         \e         escape
-         \f         formfeed
-         \n         newline
-         \r         carriage return
-         \t         tab
-         \v         vertical tab
+         \a         alarm (BEL, \x07)
+         \b         backspace (\x08)
+         \e         escape (\x27)
+         \f         formfeed (\x0c)
+         \n         newline (\x0a)
+         \qdd       set the PCRE_MATCH_LIMIT limit to dd
+                      (any number of digits)
+         \r         carriage return (\x0d)
+         \t         tab (\x09)
+         \v         vertical tab (\x0b)

          \nnn       octal character (up to 3 octal digits)
          \xhh       hexadecimal character (up to 2 hex digits)
          \x{hh...}  hexadecimal character, any number of digits
                       in UTF-8 mode
          \A         pass the PCRE_ANCHORED option to pcre_exec()
          \nnn       octal character (up to 3 octal digits)
          \xhh       hexadecimal character (up to 2 hex digits)
          \x{hh...}  hexadecimal character, any number of digits
                       in UTF-8 mode
          \A         pass the PCRE_ANCHORED option to pcre_exec()

+                      or pcre_dfa_exec()

          \B         pass the PCRE_NOTBOL option to pcre_exec()
          \B         pass the PCRE_NOTBOL option to pcre_exec()

+                      or pcre_dfa_exec()

          \Cdd       call pcre_copy_substring() for substring dd
                       after a successful match (number less than 32)
          \Cname     call pcre_copy_named_substring() for substring
          \Cdd       call pcre_copy_substring() for substring dd
                       after a successful match (number less than 32)
          \Cname     call pcre_copy_named_substring() for substring


@@ -247,6 +297,8 @@ DATA LINES
                       reached for the nth time
          \C*n       pass the number n (may be negative) as callout
                       data; this is used as the callout return value
                       reached for the nth time
          \C*n       pass the number n (may be negative) as callout
                       data; this is used as the callout return value

+         \D         use the pcre_dfa_exec() match function
+         \F         only shortest match for pcre_dfa_exec()

          \Gdd       call pcre_get_substring() for substring dd
                       after a successful match (number less than 32)
          \Gname     call pcre_get_named_substring() for substring
          \Gdd       call pcre_get_substring() for substring dd
                       after a successful match (number less than 32)
          \Gname     call pcre_get_named_substring() for substring


@@ -254,47 +306,89 @@ DATA LINES
                       ated by next non-alphanumeric character)
          \L         call pcre_get_substringlist() after a
                       successful match
                       ated by next non-alphanumeric character)
          \L         call pcre_get_substringlist() after a
                       successful match

-         \M         discover the minimum MATCH_LIMIT setting
+         \M         discover the minimum MATCH_LIMIT and
+                      MATCH_LIMIT_RECURSION settings

          \N         pass the PCRE_NOTEMPTY option to pcre_exec()
          \N         pass the PCRE_NOTEMPTY option to pcre_exec()

+                      or pcre_dfa_exec()

          \Odd       set the size of the output vector passed to
                       pcre_exec() to dd (any number of digits)
          \P         pass the PCRE_PARTIAL option to pcre_exec()
          \Odd       set the size of the output vector passed to
                       pcre_exec() to dd (any number of digits)
          \P         pass the PCRE_PARTIAL option to pcre_exec()

+                      or pcre_dfa_exec()
+         \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
+                      (any number of digits)
+         \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()

          \S         output details of memory get/free calls during matching
          \Z         pass the PCRE_NOTEOL option to pcre_exec()
          \S         output details of memory get/free calls during matching
          \Z         pass the PCRE_NOTEOL option to pcre_exec()

+                      or pcre_dfa_exec()

          \?         pass the PCRE_NO_UTF8_CHECK option to
          \?         pass the PCRE_NO_UTF8_CHECK option to

-                      pcre_exec()
+                      pcre_exec() or pcre_dfa_exec()

          \>dd       start the match at offset dd (any number of digits);
                       this sets the startoffset argument for pcre_exec()
          \>dd       start the match at offset dd (any number of digits);
                       this sets the startoffset argument for pcre_exec()

-
-       A  backslash  followed by anything else just escapes the anything else.
-       If the very last character is a backslash, it is ignored. This gives  a
-       way  of  passing  an empty line as data, since a real empty line termi-
+                      or pcre_dfa_exec()
+         \<cr>      pass the PCRE_NEWLINE_CR option to pcre_exec()
+                      or pcre_dfa_exec()
+         \<lf>      pass the PCRE_NEWLINE_LF option to pcre_exec()
+                      or pcre_dfa_exec()
+         \<crlf>    pass the PCRE_NEWLINE_CRLF option to pcre_exec()
+                      or pcre_dfa_exec()
+         \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
+                      or pcre_dfa_exec()
+
+       The escapes that specify line ending  sequences  are  literal  strings,
+       exactly as shown. No more than one newline setting should be present in
+       any data line.
+
+       A backslash followed by anything else just escapes the  anything  else.
+       If  the very last character is a backslash, it is ignored. This gives a
+       way of passing an empty line as data, since a real  empty  line  termi-

        nates the data input.
 
        nates the data input.
 

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

 
        When  \O  is  used, the value specified may be higher or lower than the
        size set by the -O command line option (or defaulted to 45); \O applies
        only to the call of pcre_exec() for the line in which it appears.
 
        If  the /P modifier was present on the pattern, causing the POSIX wrap-
 
        When  \O  is  used, the value specified may be higher or lower than the
        size set by the -O command line option (or defaulted to 45); \O applies
        only to the call of pcre_exec() for the line in which it appears.
 
        If  the /P modifier was present on the pattern, causing the POSIX wrap-

-       per API to be used, only \B and \Z have any effect, causing  REG_NOTBOL
-       and REG_NOTEOL to be passed to regexec() respectively.
+       per API to be used, the only option-setting  sequences  that  have  any
+       effect  are \B and \Z, causing REG_NOTBOL and REG_NOTEOL, respectively,
+       to be passed to regexec().
+
+       The use of \x{hh...} to represent UTF-8 characters is not dependent  on
+       the  use  of  the  /8 modifier on the pattern. It is recognized always.
+       There may be any number of hexadecimal digits inside  the  braces.  The
+       result  is from one to six bytes, encoded according to the UTF-8 rules.
+
+
+THE ALTERNATIVE MATCHING FUNCTION
+
+       By  default,  pcretest  uses  the  standard  PCRE  matching   function,
+       pcre_exec() to match each data line. From release 6.0, PCRE supports an
+       alternative matching function, pcre_dfa_test(),  which  operates  in  a
+       different  way,  and has some restrictions. The differences between the
+       two functions are described in the pcrematching documentation.
+
+       If a data line contains the \D escape sequence, or if the command  line
+       contains  the -dfa option, the alternative matching function is called.
+       This function finds all possible matches at a given point. If, however,
+       the  \F escape sequence is present in the data line, it stops after the
+       first match is found. This is always the shortest possible match.

 
 

-       The  use of \x{hh...} to represent UTF-8 characters is not dependent on
-       the use of the /8 modifier on the pattern.  It  is  recognized  always.
-       There  may  be  any number of hexadecimal digits inside the braces. The
-       result is from one to six bytes, encoded according to the UTF-8  rules.

 
 

+DEFAULT OUTPUT FROM PCRETEST

 
 

-OUTPUT FROM PCRETEST
+       This section describes the output when the  normal  matching  function,
+       pcre_exec(), is being used.

 
        When a match succeeds, pcretest outputs the list of captured substrings
        that pcre_exec() returns, starting with number 0 for  the  string  that
 
        When a match succeeds, pcretest outputs the list of captured substrings
        that pcre_exec() returns, starting with number 0 for  the  string  that


@@ -304,7 +398,7 @@ OUTPUT FROM PCRETEST
        is an example of an interactive pcretest run.
 
          $ pcretest
        is an example of an interactive pcretest run.
 
          $ pcretest

-         PCRE version 5.00 07-Sep-2004
+         PCRE version 7.0 30-Nov-2006

 
            re> /^abc(\d+)/
          data> abc123
 
            re> /^abc(\d+)/
          data> abc123


@@ -315,16 +409,17 @@ OUTPUT FROM PCRETEST
 
        If the strings contain any non-printing characters, they are output  as
        \0x  escapes,  or  as \x{...} escapes if the /8 modifier was present on
 
        If the strings contain any non-printing characters, they are output  as
        \0x  escapes,  or  as \x{...} escapes if the /8 modifier was present on

-       the pattern. If the pattern has the /+ modifier, the  output  for  sub-
-       string  0 is followed by the the rest of the subject string, identified
-       by "0+" like this:
+       the pattern. See below for the definition of  non-printing  characters.
+       If  the pattern has the /+ modifier, the output for substring 0 is fol-
+       lowed by the the rest of the subject string, identified  by  "0+"  like
+       this:

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

-       If the pattern has the /g or /G modifier,  the  results  of  successive
+       If  the  pattern  has  the /g or /G modifier, the results of successive

        matching attempts are output in sequence, like this:
 
            re> /\Bi(\w\w)/g
        matching attempts are output in sequence, like this:
 
            re> /\Bi(\w\w)/g


@@ -338,37 +433,89 @@ OUTPUT FROM PCRETEST
 
        "No match" is output only if the first match attempt fails.
 
 
        "No match" is output only if the first match attempt fails.
 

-       If  any  of the sequences \C, \G, or \L are present in a data line that
-       is successfully matched, the substrings extracted  by  the  convenience
+       If any of the sequences \C, \G, or \L are present in a data  line  that
+       is  successfully  matched,  the substrings extracted by the convenience

        functions are output with C, G, or L after the string number instead of
        a colon. This is in addition to the normal full list. The string length
        functions are output with C, G, or L after the string number instead of
        a colon. This is in addition to the normal full list. The string length

-       (that  is,  the return from the extraction function) is given in paren-
+       (that is, the return from the extraction function) is given  in  paren-

        theses after each string for \C and \G.
 
        theses after each string for \C and \G.
 

-       Note that while patterns can be continued over several lines  (a  plain
+       Note that whereas patterns can be continued over several lines (a plain

        ">" prompt is used for continuations), data lines may not. However new-
        ">" prompt is used for continuations), data lines may not. However new-

-       lines can be included in data by means of the \n escape.
+       lines  can  be included in data by means of the \n escape (or \r, \r\n,
+       etc., depending on the newline sequence setting).
+
+
+OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
+
+       When the alternative matching function, pcre_dfa_exec(),  is  used  (by
+       means  of  the \D escape sequence or the -dfa command line option), the
+       output consists of a list of all the matches that start  at  the  first
+       point in the subject where there is at least one match. For example:
+
+           re> /(tang|tangerine|tan)/
+         data> yellow tangerine\D
+          0: tangerine
+          1: tang
+          2: tan
+
+       (Using  the  normal  matching function on this data finds only "tang".)
+       The longest matching string is always given first (and numbered  zero).
+
+       If /g is present on the pattern, the search for further matches resumes
+       at the end of the longest match. For example:
+
+           re> /(tang|tangerine|tan)/g
+         data> yellow tangerine and tangy sultana\D
+          0: tangerine
+          1: tang
+          2: tan
+          0: tang
+          1: tan
+          0: tan
+
+       Since the matching function does not  support  substring  capture,  the
+       escape  sequences  that  are concerned with captured substrings are not
+       relevant.
+
+
+RESTARTING AFTER A PARTIAL MATCH
+
+       When the alternative matching function has given the PCRE_ERROR_PARTIAL
+       return,  indicating that the subject partially matched the pattern, you
+       can restart the match with additional subject data by means of  the  \R
+       escape sequence. For example:
+
+           re> /^?(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)$/
+         data> 23ja\P\D
+         Partial match: 23ja
+         data> n05\R\D
+          0: n05
+
+       For  further  information  about  partial matching, see the pcrepartial
+       documentation.

 
 
 CALLOUTS
 
        If the pattern contains any callout requests, pcretest's callout  func-
 
 
 CALLOUTS
 
        If the pattern contains any callout requests, pcretest's callout  func-

-       tion  is  called  during  matching. By default, it displays the callout
-       number, the start and current positions in  the  text  at  the  callout
-       time, and the next pattern item to be tested. For example, the output
+       tion  is  called  during  matching. This works with both matching func-
+       tions. By default, the called function displays the callout number, the
+       start  and  current  positions in the text at the callout time, and the
+       next pattern item to be tested. For example, the output

 
          --->pqrabcdef
            0    ^  ^     \d
 
 
          --->pqrabcdef
            0    ^  ^     \d
 

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

        are the same.
 
        Callouts numbered 255 are assumed to be automatic callouts, inserted as
        are the same.
 
        Callouts numbered 255 are assumed to be automatic callouts, inserted as

-       a result of the /C pattern modifier. In this case, instead  of  showing
-       the  callout  number, the offset in the pattern, preceded by a plus, is
+       a  result  of the /C pattern modifier. In this case, instead of showing
+       the callout number, the offset in the pattern, preceded by a  plus,  is

        output. For example:
 
            re> /\d?[A-E]\*/C
        output. For example:
 
            re> /\d?[A-E]\*/C


@@ -380,76 +527,94 @@ CALLOUTS
          +10 ^ ^
           0: E*
 
          +10 ^ ^
           0: E*
 

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

        to change this.
 
        to change this.
 

-       Inserting callouts can be helpful when using pcretest to check  compli-
-       cated  regular expressions. For further information about callouts, see
+       Inserting  callouts can be helpful when using pcretest to check compli-
+       cated regular expressions. For further information about callouts,  see

        the pcrecallout documentation.
 
 
        the pcrecallout documentation.
 
 

+NON-PRINTING CHARACTERS
+
+       When  pcretest is outputting text in the compiled version of a pattern,
+       bytes other than 32-126 are always treated as  non-printing  characters
+       are are therefore shown as hex escapes.
+
+       When  pcretest  is  outputting text that is a matched part of a subject
+       string, it behaves in the same way, unless a different locale has  been
+       set  for  the  pattern  (using  the  /L  modifier).  In  this case, the
+       isprint() function to distinguish printing and non-printing characters.
+
+

 SAVING AND RELOADING COMPILED PATTERNS
 
 SAVING AND RELOADING COMPILED PATTERNS
 

-       The facilities described in this section are  not  available  when  the
+       The  facilities  described  in  this section are not available when the

        POSIX inteface to PCRE is being used, that is, when the /P pattern mod-
        ifier is specified.
 
        When the POSIX interface is not in use, you can cause pcretest to write
        POSIX inteface to PCRE is being used, that is, when the /P pattern mod-
        ifier is specified.
 
        When the POSIX interface is not in use, you can cause pcretest to write

-       a  compiled  pattern to a file, by following the modifiers with > and a
+       a compiled pattern to a file, by following the modifiers with >  and  a

        file name.  For example:
 
          /pattern/im >/some/file
 
        file name.  For example:
 
          /pattern/im >/some/file
 

-       See the pcreprecompile documentation for a discussion about saving  and
+       See  the pcreprecompile documentation for a discussion about saving and

        re-using compiled patterns.
 
        re-using compiled patterns.
 

-       The  data  that  is  written  is  binary. The first eight bytes are the
-       length of the compiled pattern data  followed  by  the  length  of  the
-       optional  study  data,  each  written as four bytes in big-endian order
-       (most significant byte first). If there is no study  data  (either  the
+       The data that is written is binary.  The  first  eight  bytes  are  the
+       length  of  the  compiled  pattern  data  followed by the length of the
+       optional study data, each written as four  bytes  in  big-endian  order
+       (most  significant  byte  first). If there is no study data (either the

        pattern was not studied, or studying did not return any data), the sec-
        pattern was not studied, or studying did not return any data), the sec-

-       ond length is zero. The lengths are followed by an exact  copy  of  the
+       ond  length  is  zero. The lengths are followed by an exact copy of the

        compiled pattern. If there is additional study data, this follows imme-
        compiled pattern. If there is additional study data, this follows imme-

-       diately after the compiled pattern. After writing  the  file,  pcretest
+       diately  after  the  compiled pattern. After writing the file, pcretest

        expects to read a new pattern.
 
        A saved pattern can be reloaded into pcretest by specifing < and a file
        expects to read a new pattern.
 
        A saved pattern can be reloaded into pcretest by specifing < and a file

-       name instead of a pattern. The name of the file must not  contain  a  <
-       character,  as  otherwise pcretest will interpret the line as a pattern
+       name  instead  of  a pattern. The name of the file must not contain a <
+       character, as otherwise pcretest will interpret the line as  a  pattern

        delimited by < characters.  For example:
 
           re> </some/file
          Compiled regex loaded from /some/file
          No study data
 
        delimited by < characters.  For example:
 
           re> </some/file
          Compiled regex loaded from /some/file
          No study data
 

-       When the pattern has been loaded, pcretest proceeds to read data  lines
+       When  the pattern has been loaded, pcretest proceeds to read data lines

        in the usual way.
 
        in the usual way.
 

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

        machine and run on a SPARC machine.
 
        machine and run on a SPARC machine.
 

-       File names for saving and reloading can be absolute  or  relative,  but
-       note  that the shell facility of expanding a file name that starts with
+       File  names  for  saving and reloading can be absolute or relative, but
+       note that the shell facility of expanding a file name that starts  with

        a tilde (~) is not available.
 
        a tilde (~) is not available.
 

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

        a file that is not in the correct format, the result is undefined.
 
 
        a file that is not in the correct format, the result is undefined.
 
 

+SEE ALSO
+
+       pcre(3), pcreapi(3), pcrecallout(3),  pcrematching(3),  pcrepartial(d),
+       pcrepattern(3), pcreprecompile(3).
+
+

 AUTHOR
 
 AUTHOR
 

-       Philip Hazel <ph10@cam.ac.uk>
+       Philip Hazel

        University Computing Service,
        University Computing Service,

-       Cambridge CB2 3QG, England.
+       Cambridge CB2 3QH, England.

 
 

-Last updated: 10 September 2004
-Copyright (c) 1997-2004 University of Cambridge.
+Last updated: 30 November 2006
+Copyright (c) 1997-2006 University of Cambridge.