Documentation update.

git-svn-id: svn://vcs.exim.org/pcre2/code/trunk@829 6239d852-aaf2-0410-a92c-79f79f948069

1 files changed, 275 insertions, 250 deletions

diff --git a/doc/pcre2test.txt b/doc/pcre2test.txt
index 60d81ac..32ac6d6 100644
--- a/doc/pcre2test.txt
+++ b/doc/pcre2test.txt
@@ -64,12 +64,12 @@ INPUT ENCODING
        unless you really want that action.
 
        The  input  is  processed using using C's string functions, so must not
-       contain binary zeroes, even though in Unix-like  environments,  fgets()
+       contain binary zeros, even though in  Unix-like  environments,  fgets()
        treats  any  bytes  other  than newline as data characters. An error is
-       generated if a binary zero is encountered. Subject lines are  processed
-       for  backslash  escapes,  which  makes  it possible to include any data
-       value in strings that are passed to the library for matching. For  pat-
-       terns,  there  is  a  facility  for specifying some or all of the 8-bit
+       generated if a binary zero is encountered. By default subject lines are
+       processed for backslash escapes, which makes it possible to include any
+       data value in strings that are passed to the library for matching.  For
+       patterns,  there  is a facility for specifying some or all of the 8-bit
        input characters as hexadecimal  pairs,  which  makes  it  possible  to
        include binary zeros.
 
@@ -319,9 +319,9 @@ COMMAND LINES
 
        When  the  POSIX  API  is  being tested there is no way to override the
        default newline convention, though it is possible to  set  the  newline
-       convention  from  within  the  pattern. A warning is given if the posix
-       modifier is used when #newline_default would set a default for the non-
-       POSIX API.
+       convention  from within the pattern. A warning is given if the posix or
+       posix_nosub modifier is used when #newline_default would set a  default
+       for the non-POSIX API.
 
          #pattern <modifier-list>
 
@@ -424,8 +424,9 @@ SUBJECT LINE SYNTAX
 
        Before   each   subject   line   is   passed   to   pcre2_match()    or
        pcre2_dfa_match(), leading and trailing white space is removed, and the
-       line is scanned for backslash escapes. The following provide a means of
-       encoding non-printing characters in a visible way:
+       line is scanned for backslash escapes, unless the subject_literal modi-
+       fier was set for the pattern. The following provide a means of encoding
+       non-printing characters in a visible way:
 
          \a         alarm (BEL, \x07)
          \b         backspace (\x08)
@@ -442,23 +443,23 @@ SUBJECT LINE SYNTAX
          \x{hh...}  hexadecimal character (any number of hex digits)
 
        The use of \x{hh...} is not dependent on the use of the utf modifier on
-       the pattern. It is recognized always. There may be any number of  hexa-
-       decimal  digits  inside  the  braces; invalid values provoke error mes-
+       the  pattern. It is recognized always. There may be any number of hexa-
+       decimal digits inside the braces; invalid  values  provoke  error  mes-
        sages.
 
-       Note that \xhh specifies one byte rather than one  character  in  UTF-8
-       mode;  this  makes it possible to construct invalid UTF-8 sequences for
-       testing purposes. On the other hand, \x{hh} is interpreted as  a  UTF-8
-       character  in UTF-8 mode, generating more than one byte if the value is
-       greater than 127.  When testing the 8-bit library not  in  UTF-8  mode,
+       Note  that  \xhh  specifies one byte rather than one character in UTF-8
+       mode; this makes it possible to construct invalid UTF-8  sequences  for
+       testing  purposes.  On the other hand, \x{hh} is interpreted as a UTF-8
+       character in UTF-8 mode, generating more than one byte if the value  is
+       greater  than  127.   When testing the 8-bit library not in UTF-8 mode,
        \x{hh} generates one byte for values less than 256, and causes an error
        for greater values.
 
        In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it
        possible to construct invalid UTF-16 sequences for testing purposes.
 
-       In  UTF-32  mode,  all  4- to 8-digit \x{...} values are accepted. This
-       makes it possible to construct invalid  UTF-32  sequences  for  testing
+       In UTF-32 mode, all 4- to 8-digit \x{...}  values  are  accepted.  This
+       makes  it  possible  to  construct invalid UTF-32 sequences for testing
        purposes.
 
        There is a special backslash sequence that specifies replication of one
@@ -466,33 +467,38 @@ SUBJECT LINE SYNTAX
 
          \[<characters>]{<count>}
 
-       This makes it possible to test long strings without having  to  provide
+       This  makes  it possible to test long strings without having to provide
        them as part of the file. For example:
 
          \[abc]{4}
 
-       is  converted to "abcabcabcabc". This feature does not support nesting.
+       is converted to "abcabcabcabc". This feature does not support  nesting.
        To include a closing square bracket in the characters, code it as \x5D.
 
-       A backslash followed by an equals sign marks the  end  of  the  subject
+       A  backslash  followed  by  an equals sign marks the end of the subject
        string and the start of a modifier list. For example:
 
          abc\=notbol,notempty
 
-       If  the  subject  string is empty and \= is followed by whitespace, the
-       line is treated as a comment line, and is not used  for  matching.  For
+       If the subject string is empty and \= is followed  by  whitespace,  the
+       line  is  treated  as a comment line, and is not used for matching. For
        example:
 
          \= This is a comment.
          abc\= This is an invalid modifier list.
 
-       A  backslash  followed  by  any  other  non-alphanumeric character just
+       A backslash followed  by  any  other  non-alphanumeric  character  just
        escapes that character. A backslash followed by anything else causes an
-       error.  However,  if the very last character in the line is a backslash
-       (and there is no modifier list), it is ignored. This  gives  a  way  of
-       passing  an  empty line as data, since a real empty line terminates the
+       error. However, if the very last character in the line is  a  backslash
+       (and  there  is  no  modifier list), it is ignored. This gives a way of
+       passing an empty line as data, since a real empty line  terminates  the
        data input.
 
+       If the subject_literal modifier is set for a pattern, all subject lines
+       that follow are treated as literals, with no special treatment of back-
+       slashes.  No replication is possible, and any subject modifiers must be
+       set as defaults by a #subject command.
+
 
 PATTERN MODIFIERS
 
@@ -530,7 +536,10 @@ PATTERN MODIFIERS
          /x  extended                  set PCRE2_EXTENDED
          /xx extended_more             set PCRE2_EXTENDED_MORE
              firstline                 set PCRE2_FIRSTLINE
+             literal                   set PCRE2_LITERAL
+             match_line                set PCRE2_EXTRA_MATCH_LINE
              match_unset_backref       set PCRE2_MATCH_UNSET_BACKREF
+             match_word                set PCRE2_EXTRA_MATCH_WORD
          /m  multiline                 set PCRE2_MULTILINE
              never_backslash_c         set PCRE2_NEVER_BACKSLASH_C
              never_ucp                 set PCRE2_NEVER_UCP
@@ -580,6 +589,7 @@ PATTERN MODIFIERS
              push                      push compiled pattern onto the stack
              pushcopy                  push a copy onto the stack
              stackguard=<number>       test the stackguard feature
+             subject_literal           treat all subject lines as literal
              tables=[0|1|2]            select internal tables
              use_length                do not zero-terminate the pattern
              utf8_input                treat input as UTF-8
@@ -659,16 +669,6 @@ PATTERN MODIFIERS
        testing that pcre2_compile() behaves correctly in this  case  (it  uses
        default values).
 
-   Specifying the pattern's length
-
-       By default, patterns are passed to the compiling functions as zero-ter-
-       minated strings. When using the POSIX wrapper API, there  is  no  other
-       option.  However, when using PCRE2's native API, patterns can be passed
-       by length instead of being  zero-terminated.  The  use_length  modifier
-       causes  this  to happen.  Using a length happens automatically (whether
-       or not use_length is set) when hex is set, because  patterns  specified
-       in hexadecimal may contain binary zeros.
-
    Specifying pattern characters in hexadecimal
 
        The  hex  modifier specifies that the characters of the pattern, except
@@ -690,61 +690,68 @@ PATTERN MODIFIERS
        ing  the delimiter within a substring. The hex and expand modifiers are
        mutually exclusive.
 
-       The POSIX API cannot be used with  patterns  specified  in  hexadecimal
-       because they may contain binary zeros, which conflicts with regcomp()'s
-       requirement for a zero-terminated  string.  Such  patterns  are  always
-       passed to pcre2_compile() as a string with a length, not as zero-termi-
-       nated.
+   Specifying the pattern's length
+
+       By default, patterns are passed to the compiling functions as zero-ter-
+       minated  strings but can be passed by length instead of being zero-ter-
+       minated. The use_length modifier causes this to happen. Using a  length
+       happens  automatically  (whether  or not use_length is set) when hex is
+       set, because patterns  specified  in  hexadecimal  may  contain  binary
+       zeros.
+
+       If hex or use_length is used with the POSIX wrapper API (see "Using the
+       POSIX wrapper API" below), the REG_PEND extension is used to  pass  the
+       pattern's length.
 
    Specifying wide characters in 16-bit and 32-bit modes
 
        In 16-bit and 32-bit modes, all input is automatically treated as UTF-8
-       and  translated  to  UTF-16 or UTF-32 when the utf modifier is set. For
+       and translated to UTF-16 or UTF-32 when the utf modifier  is  set.  For
        testing the 16-bit and 32-bit libraries in non-UTF mode, the utf8_input
-       modifier  can  be  used. It is mutually exclusive with utf. Input lines
+       modifier can be used. It is mutually exclusive with  utf.  Input  lines
        are interpreted as UTF-8 as a means of specifying wide characters. More
        details are given in "Input encoding" above.
 
    Generating long repetitive patterns
 
-       Some  tests use long patterns that are very repetitive. Instead of cre-
-       ating a very long input line for such a pattern, you can use a  special
-       repetition  feature,  similar  to  the  one described for subject lines
-       above. If the expand modifier is present on a  pattern,  parts  of  the
+       Some tests use long patterns that are very repetitive. Instead of  cre-
+       ating  a very long input line for such a pattern, you can use a special
+       repetition feature, similar to the  one  described  for  subject  lines
+       above.  If  the  expand  modifier is present on a pattern, parts of the
        pattern that have the form
 
          \[<characters>]{<count>}
 
        are expanded before the pattern is passed to pcre2_compile(). For exam-
        ple, \[AB]{6000} is expanded to "ABAB..." 6000 times. This construction
-       cannot  be  nested. An initial "\[" sequence is recognized only if "]{"
-       followed by decimal digits and "}" is found later in  the  pattern.  If
+       cannot be nested. An initial "\[" sequence is recognized only  if  "]{"
+       followed  by  decimal  digits and "}" is found later in the pattern. If
        not, the characters remain in the pattern unaltered. The expand and hex
        modifiers are mutually exclusive.
 
-       If part of an expanded pattern looks like an expansion, but  is  really
+       If  part  of an expanded pattern looks like an expansion, but is really
        part of the actual pattern, unwanted expansion can be avoided by giving
        two values in the quantifier. For example, \[AB]{6000,6000} is not rec-
        ognized as an expansion item.
 
-       If  the  info modifier is set on an expanded pattern, the result of the
+       If the info modifier is set on an expanded pattern, the result  of  the
        expansion is included in the information that is output.
 
    JIT compilation
 
-       Just-in-time (JIT) compiling is a  heavyweight  optimization  that  can
-       greatly  speed  up pattern matching. See the pcre2jit documentation for
-       details. JIT compiling happens, optionally, after a  pattern  has  been
-       successfully  compiled into an internal form. The JIT compiler converts
+       Just-in-time  (JIT)  compiling  is  a heavyweight optimization that can
+       greatly speed up pattern matching. See the pcre2jit  documentation  for
+       details.  JIT  compiling  happens, optionally, after a pattern has been
+       successfully compiled into an internal form. The JIT compiler  converts
        this to optimized machine code. It needs to know whether the match-time
        options PCRE2_PARTIAL_HARD and PCRE2_PARTIAL_SOFT are going to be used,
-       because different code is generated for the different  cases.  See  the
-       partial  modifier in "Subject Modifiers" below for details of how these
+       because  different  code  is generated for the different cases. See the
+       partial modifier in "Subject Modifiers" below for details of how  these
        options are specified for each match attempt.
 
-       JIT compilation is requested by the /jit pattern  modifier,  which  may
+       JIT  compilation  is  requested  by the jit pattern modifier, which may
        optionally be followed by an equals sign and a number in the range 0 to
-       7.  The three bits that make up the number specify which of  the  three
+       7.   The  three bits that make up the number specify which of the three
        JIT operating modes are to be compiled:
 
          1  compile JIT code for non-partial matching
@@ -761,31 +768,31 @@ PATTERN MODIFIERS
          6  soft and hard partial matching only
          7  all three modes
 
-       If  no  number  is  given,  7 is assumed. The phrase "partial matching"
+       If no number is given, 7 is  assumed.  The  phrase  "partial  matching"
        means a call to pcre2_match() with either the PCRE2_PARTIAL_SOFT or the
-       PCRE2_PARTIAL_HARD  option set. Note that such a call may return a com-
+       PCRE2_PARTIAL_HARD option set. Note that such a call may return a  com-
        plete match; the options enable the possibility of a partial match, but
-       do  not  require it. Note also that if you request JIT compilation only
-       for partial matching (for example, /jit=2) but do not set  the  partial
-       modifier  on  a  subject line, that match will not use JIT code because
+       do not require it. Note also that if you request JIT  compilation  only
+       for  partial  matching  (for example, jit=2) but do not set the partial
+       modifier on a subject line, that match will not use  JIT  code  because
        none was compiled for non-partial matching.
 
-       If JIT compilation is successful, the compiled JIT code will  automati-
-       cally  be  used  when  an appropriate type of match is run, except when
-       incompatible run-time options are specified. For more details, see  the
-       pcre2jit  documentation. See also the jitstack modifier below for a way
+       If  JIT compilation is successful, the compiled JIT code will automati-
+       cally be used when an appropriate type of match  is  run,  except  when
+       incompatible  run-time options are specified. For more details, see the
+       pcre2jit documentation. See also the jitstack modifier below for a  way
        of setting the size of the JIT stack.
 
-       If the jitfast modifier is specified, matching is done  using  the  JIT
-       "fast  path" interface, pcre2_jit_match(), which skips some of the san-
-       ity checks that are done by pcre2_match(), and of course does not  work
-       when  JIT  is not supported. If jitfast is specified without jit, jit=7
+       If  the  jitfast  modifier is specified, matching is done using the JIT
+       "fast path" interface, pcre2_jit_match(), which skips some of the  san-
+       ity  checks that are done by pcre2_match(), and of course does not work
+       when JIT is not supported. If jitfast is specified without  jit,  jit=7
        is assumed.
 
-       If the jitverify modifier is specified, information about the  compiled
-       pattern  shows  whether  JIT  compilation was or was not successful. If
-       jitverify is specified without jit, jit=7 is assumed. If  JIT  compila-
-       tion  is successful when jitverify is set, the text "(JIT)" is added to
+       If  the jitverify modifier is specified, information about the compiled
+       pattern shows whether JIT compilation was or  was  not  successful.  If
+       jitverify  is  specified without jit, jit=7 is assumed. If JIT compila-
+       tion is successful when jitverify is set, the text "(JIT)" is added  to
        the first output line after a match or non match when JIT-compiled code
        was actually used in the match.
 
@@ -796,19 +803,19 @@ PATTERN MODIFIERS
          /pattern/locale=fr_FR
 
        The given locale is set, pcre2_maketables() is called to build a set of
-       character tables for the locale, and this is then passed to  pcre2_com-
-       pile()  when compiling the regular expression. The same tables are used
-       when matching the following subject lines. The locale modifier  applies
+       character  tables for the locale, and this is then passed to pcre2_com-
+       pile() when compiling the regular expression. The same tables are  used
+       when  matching the following subject lines. The locale modifier applies
        only to the pattern on which it appears, but can be given in a #pattern
-       command if a default is needed. Setting a locale and alternate  charac-
+       command  if a default is needed. Setting a locale and alternate charac-
        ter tables are mutually exclusive.
 
    Showing pattern memory
 
        The memory modifier causes the size in bytes of the memory used to hold
-       the compiled pattern to be output. This does not include  the  size  of
-       the  pcre2_code block; it is just the actual compiled data. If the pat-
-       tern is subsequently passed to the JIT compiler, the size  of  the  JIT
+       the  compiled  pattern  to be output. This does not include the size of
+       the pcre2_code block; it is just the actual compiled data. If the  pat-
+       tern  is  subsequently  passed to the JIT compiler, the size of the JIT
        compiled code is also output. Here is an example:
 
            re> /a(b)c/jit,memory
@@ -818,27 +825,27 @@ PATTERN MODIFIERS
 
    Limiting nested parentheses
 
-       The  parens_nest_limit  modifier  sets  a  limit on the depth of nested
-       parentheses in a pattern. Breaching  the  limit  causes  a  compilation
-       error.   The  default  for  the library is set when PCRE2 is built, but
-       pcre2test sets its own default of 220, which is  required  for  running
+       The parens_nest_limit modifier sets a limit  on  the  depth  of  nested
+       parentheses  in  a  pattern.  Breaching  the limit causes a compilation
+       error.  The default for the library is set when  PCRE2  is  built,  but
+       pcre2test  sets  its  own default of 220, which is required for running
        the standard test suite.
 
    Limiting the pattern length
 
-       The  max_pattern_length  modifier  sets  a limit, in code units, to the
+       The max_pattern_length modifier sets a limit, in  code  units,  to  the
        length of pattern that pcre2_compile() will accept. Breaching the limit
-       causes  a  compilation  error.  The  default  is  the  largest number a
+       causes a compilation  error.  The  default  is  the  largest  number  a
        PCRE2_SIZE variable can hold (essentially unlimited).
 
    Using the POSIX wrapper API
 
-       The /posix and posix_nosub modifiers cause pcre2test to call PCRE2  via
-       the  POSIX  wrapper API rather than its native API. When posix_nosub is
-       used, the POSIX option REG_NOSUB is  passed  to  regcomp().  The  POSIX
-       wrapper  supports  only  the 8-bit library. Note that it does not imply
+       The  posix  and posix_nosub modifiers cause pcre2test to call PCRE2 via
+       the POSIX wrapper API rather than its native API. When  posix_nosub  is
+       used,  the  POSIX  option  REG_NOSUB  is passed to regcomp(). The POSIX
+       wrapper supports only the 8-bit library. Note that it  does  not  imply
        POSIX matching semantics; for more detail see the pcre2posix documenta-
-       tion.  The  following  pattern  modifiers set options for the regcomp()
+       tion. The following pattern modifiers set  options  for  the  regcomp()
        function:
 
          caseless           REG_ICASE
@@ -848,35 +855,39 @@ PATTERN MODIFIERS
          ucp                REG_UCP        )   the POSIX standard
          utf                REG_UTF8       )
 
-       The regerror_buffsize modifier specifies a size for  the  error  buffer
-       that  is  passed to regerror() in the event of a compilation error. For
+       The  regerror_buffsize  modifier  specifies a size for the error buffer
+       that is passed to regerror() in the event of a compilation  error.  For
        example:
 
          /abc/posix,regerror_buffsize=20
 
-       This provides a means of testing the behaviour of regerror()  when  the
-       buffer  is  too  small  for the error message. If this modifier has not
+       This  provides  a means of testing the behaviour of regerror() when the
+       buffer is too small for the error message. If  this  modifier  has  not
        been set, a large buffer is used.
 
-       The aftertext and allaftertext  subject  modifiers  work  as  described
-       below.  All other modifiers are either ignored, with a warning message,
+       The  aftertext  and  allaftertext  subject  modifiers work as described
+       below. All other modifiers are either ignored, with a warning  message,
        or cause an error.
 
+       The  pattern  is  passed  to  regcomp()  as a zero-terminated string by
+       default, but if the use_length or hex modifiers are set,  the  REG_PEND
+       extension is used to pass it by length.
+
    Testing the stack guard feature
 
-       The stackguard modifier is used  to  test  the  use  of  pcre2_set_com-
-       pile_recursion_guard(),  a  function  that  is provided to enable stack
-       availability to be checked during compilation (see the  pcre2api  docu-
-       mentation  for  details).  If  the  number specified by the modifier is
+       The  stackguard  modifier  is  used  to  test the use of pcre2_set_com-
+       pile_recursion_guard(), a function that is  provided  to  enable  stack
+       availability  to  be checked during compilation (see the pcre2api docu-
+       mentation for details). If the number  specified  by  the  modifier  is
        greater than zero, pcre2_set_compile_recursion_guard() is called to set
-       up  callback  from pcre2_compile() to a local function. The argument it
-       receives is the current nesting parenthesis depth; if this  is  greater
+       up callback from pcre2_compile() to a local function. The  argument  it
+       receives  is  the current nesting parenthesis depth; if this is greater
        than the value given by the modifier, non-zero is returned, causing the
        compilation to be aborted.
 
    Using alternative character tables
 
-       The value specified for the tables modifier must be one of  the  digits
+       The  value  specified for the tables modifier must be one of the digits
        0, 1, or 2. It causes a specific set of built-in character tables to be
        passed to pcre2_compile(). This is used in the PCRE2 tests to check be-
        haviour with different character tables. The digit specifies the tables
@@ -887,23 +898,25 @@ PATTERN MODIFIERS
                pcre2_chartables.c.dist
          2   a set of tables defining ISO 8859 characters
 
-       In table 2, some characters whose codes are greater than 128 are  iden-
-       tified  as  letters,  digits,  spaces, etc. Setting alternate character
+       In  table 2, some characters whose codes are greater than 128 are iden-
+       tified as letters, digits, spaces,  etc.  Setting  alternate  character
        tables and a locale are mutually exclusive.
 
    Setting certain match controls
 
        The following modifiers are really subject modifiers, and are described
-       below.   However, they may be included in a pattern's modifier list, in
-       which case they are applied to every subject  line  that  is  processed
-       with that pattern. They may not appear in #pattern commands. These mod-
-       ifiers do not affect the compilation process.
+       under "Subject Modifiers" below. However, they may  be  included  in  a
+       pattern's  modifier  list, in which case they are applied to every sub-
+       ject line that is processed with that pattern. They may not  appear  in
+       #pattern  commands.   These  modifiers  do  not  affect the compilation
+       process.
 
              aftertext                  show text after match
              allaftertext               show text after captures
              allcaptures                show all captures
              allusedtext                show all consulted text
          /g  global                     global matching
+             jitstack=<n>               set size of JIT stack
              mark                       show mark values
              replace=<string>           specify a replacement string
              startchar                  show starting character when relevant
@@ -915,6 +928,14 @@ PATTERN MODIFIERS
        These modifiers may not appear in a #pattern command. If you want  them
        as defaults, set them in a #subject command.
 
+   Specifying literal subject lines
+
+       If  the  subject_literal modifier is present on a pattern, all the sub-
+       ject lines that it matches are taken as literal strings, with no inter-
+       pretation  of  backslashes. It is not possible to set subject modifiers
+       on such lines, but any that are set as defaults by a  #subject  command
+       are recognized.
+
    Saving a compiled pattern
 
        When  a  pattern with the push modifier is successfully compiled, it is
@@ -959,11 +980,11 @@ SUBJECT MODIFIERS
        The partial matching modifiers are provided with abbreviations  because
        they appear frequently in tests.
 
-       If  the  posix  modifier  was present on the pattern, causing the POSIX
-       wrapper API to be used, the only option-setting modifiers that have any
-       effect   are   notbol,   notempty,   and  noteol,  causing  REG_NOTBOL,
-       REG_NOTEMPTY, and REG_NOTEOL, respectively, to be passed to  regexec().
-       The other modifiers are ignored, with a warning message.
+       If  the posix or posix_nosub modifier was present on the pattern, caus-
+       ing the POSIX wrapper API to be used, the only option-setting modifiers
+       that have any effect are notbol, notempty, and noteol, causing REG_NOT-
+       BOL, REG_NOTEMPTY,  and  REG_NOTEOL,  respectively,  to  be  passed  to
+       regexec(). The other modifiers are ignored, with a warning message.
 
        There  is one additional modifier that can be used with the POSIX wrap-
        per. It is ignored (with a warning) if used for non-POSIX matching.
@@ -971,16 +992,19 @@ SUBJECT MODIFIERS
              posix_startend=<n>[:<m>]
 
        This causes the subject string to be  passed  to  regexec()  using  the
-       REG_STARTEND  option,  which uses offsets to restrict which part of the
+       REG_STARTEND  option,  which  uses offsets to specify which part of the
        string is searched. If only one number is  given,  the  end  offset  is
        passed  as  the end of the subject string. For more detail of REG_STAR-
-       TEND, see the pcre2posix documentation.
+       TEND, see the pcre2posix documentation. If the subject string  contains
+       binary  zeros  (coded  as escapes such as \x{00} because pcre2test does
+       not support actual binary zeros in its input), you must use posix_star-
+       tend to specify its length.
 
    Setting match controls
 
-       The following modifiers affect the matching process  or  request  addi-
-       tional  information.  Some  of  them may also be specified on a pattern
-       line (see above), in which case they apply to every subject  line  that
+       The  following  modifiers  affect the matching process or request addi-
+       tional information. Some of them may also be  specified  on  a  pattern
+       line  (see  above), in which case they apply to every subject line that
        is matched against that pattern.
 
              aftertext                  show text after match
@@ -1020,29 +1044,29 @@ SUBJECT MODIFIERS
              zero_terminate             pass the subject as zero-terminated
 
        The effects of these modifiers are described in the following sections.
-       When matching via the POSIX wrapper API, the  aftertext,  allaftertext,
-       and  ovector subject modifiers work as described below. All other modi-
+       When  matching  via the POSIX wrapper API, the aftertext, allaftertext,
+       and ovector subject modifiers work as described below. All other  modi-
        fiers are either ignored, with a warning message, or cause an error.
 
    Showing more text
 
-       The aftertext modifier requests that as well as outputting the part  of
+       The  aftertext modifier requests that as well as outputting the part of
        the subject string that matched the entire pattern, pcre2test should in
        addition output the remainder of the subject string. This is useful for
        tests where the subject contains multiple copies of the same substring.
-       The allaftertext modifier requests the same action  for  captured  sub-
+       The  allaftertext  modifier  requests the same action for captured sub-
        strings as well as the main matched substring. In each case the remain-
        der is output on the following line with a plus character following the
        capture number.
 
-       The  allusedtext modifier requests that all the text that was consulted
-       during a successful pattern match by the interpreter should  be  shown.
-       This  feature  is not supported for JIT matching, and if requested with
-       JIT it is ignored (with  a  warning  message).  Setting  this  modifier
+       The allusedtext modifier requests that all the text that was  consulted
+       during  a  successful pattern match by the interpreter should be shown.
+       This feature is not supported for JIT matching, and if  requested  with
+       JIT  it  is  ignored  (with  a  warning message). Setting this modifier
        affects the output if there is a lookbehind at the start of a match, or
-       a lookahead at the end, or if \K is used  in  the  pattern.  Characters
-       that  precede or follow the start and end of the actual match are indi-
-       cated in the output by '<' or '>' characters underneath them.  Here  is
+       a  lookahead  at  the  end, or if \K is used in the pattern. Characters
+       that precede or follow the start and end of the actual match are  indi-
+       cated  in  the output by '<' or '>' characters underneath them. Here is
        an example:
 
            re> /(?<=pqr)abc(?=xyz)/
@@ -1050,16 +1074,16 @@ SUBJECT MODIFIERS
           0: pqrabcxyz
              <<<   >>>
 
-       This  shows  that  the  matched string is "abc", with the preceding and
-       following strings "pqr" and "xyz"  having  been  consulted  during  the
+       This shows that the matched string is "abc",  with  the  preceding  and
+       following  strings  "pqr"  and  "xyz"  having been consulted during the
        match (when processing the assertions).
 
-       The  startchar  modifier  requests  that the starting character for the
-       match be indicated, if it is different to  the  start  of  the  matched
+       The startchar modifier requests that the  starting  character  for  the
+       match  be  indicated,  if  it  is different to the start of the matched
        string. The only time when this occurs is when \K has been processed as
        part of the match. In this situation, the output for the matched string
-       is  displayed  from  the  starting  character instead of from the match
-       point, with circumflex characters under  the  earlier  characters.  For
+       is displayed from the starting character  instead  of  from  the  match
+       point,  with  circumflex  characters  under the earlier characters. For
        example:
 
            re> /abc\Kxyz/
@@ -1067,7 +1091,7 @@ SUBJECT MODIFIERS
           0: abcxyz
              ^^^
 
-       Unlike  allusedtext, the startchar modifier can be used with JIT.  How-
+       Unlike allusedtext, the startchar modifier can be used with JIT.   How-
        ever, these two modifiers are mutually exclusive.
 
    Showing the value of all capture groups
@@ -1075,98 +1099,98 @@ SUBJECT MODIFIERS
        The allcaptures modifier requests that the values of all potential cap-
        tured parentheses be output after a match. By default, only those up to
        the highest one actually used in the match are output (corresponding to
-       the  return  code from pcre2_match()). Groups that did not take part in
-       the match are output as "<unset>". This modifier is  not  relevant  for
-       DFA  matching  (which does no capturing); it is ignored, with a warning
+       the return code from pcre2_match()). Groups that did not take  part  in
+       the  match  are  output as "<unset>". This modifier is not relevant for
+       DFA matching (which does no capturing); it is ignored, with  a  warning
        message, if present.
 
    Testing callouts
 
-       A callout function is supplied when pcre2test calls the library  match-
-       ing  functions, unless callout_none is specified. If callout_capture is
-       set, the current captured groups are output when a callout occurs.  The
+       A  callout function is supplied when pcre2test calls the library match-
+       ing functions, unless callout_none is specified. If callout_capture  is
+       set,  the current captured groups are output when a callout occurs. The
        default return from the callout function is zero, which allows matching
        to continue.
 
-       The callout_fail modifier can be given one or two numbers. If there  is
-       only  one number, 1 is returned instead of 0 (causing matching to back-
-       track) when a callout  of  that  number  is  reached.  If  two  numbers
-       (<n>:<m>)  are  given,  1  is  returned when callout <n> is reached and
-       there have been at least <m> callouts. The  callout_error  modifier  is
-       similar,  except  that  PCRE2_ERROR_CALLOUT  is  returned,  causing the
-       entire matching process to be aborted. If both these modifiers are  set
+       The  callout_fail modifier can be given one or two numbers. If there is
+       only one number, 1 is returned instead of 0 (causing matching to  back-
+       track)  when  a  callout  of  that  number  is  reached. If two numbers
+       (<n>:<m>) are given, 1 is returned when  callout  <n>  is  reached  and
+       there  have  been  at least <m> callouts. The callout_error modifier is
+       similar, except  that  PCRE2_ERROR_CALLOUT  is  returned,  causing  the
+       entire  matching process to be aborted. If both these modifiers are set
        for the same callout number, callout_error takes precedence.
 
-       Note  that  callouts  with string arguments are always given the number
+       Note that callouts with string arguments are always  given  the  number
        zero. See "Callouts" below for a description of the output when a call-
        out it taken.
 
-       The  callout_data  modifier can be given an unsigned or a negative num-
-       ber.  This is set as the "user data" that is  passed  to  the  matching
-       function,  and  passed  back  when the callout function is invoked. Any
-       value other than zero is used as  a  return  from  pcre2test's  callout
+       The callout_data modifier can be given an unsigned or a  negative  num-
+       ber.   This  is  set  as the "user data" that is passed to the matching
+       function, and passed back when the callout  function  is  invoked.  Any
+       value  other  than  zero  is  used as a return from pcre2test's callout
        function.
 
    Finding all matches in a string
 
        Searching for all possible matches within a subject can be requested by
-       the global or altglobal modifier. After finding a match,  the  matching
-       function  is  called  again to search the remainder of the subject. The
-       difference between global and altglobal is that  the  former  uses  the
-       start_offset  argument  to  pcre2_match() or pcre2_dfa_match() to start
-       searching at a new point within the entire string (which is  what  Perl
+       the  global  or altglobal modifier. After finding a match, the matching
+       function is called again to search the remainder of  the  subject.  The
+       difference  between  global  and  altglobal is that the former uses the
+       start_offset argument to pcre2_match() or  pcre2_dfa_match()  to  start
+       searching  at  a new point within the entire string (which is what Perl
        does), whereas the latter passes over a shortened subject. This makes a
        difference to the matching process if the pattern begins with a lookbe-
        hind assertion (including \b or \B).
 
-       If  an  empty  string  is  matched,  the  next  match  is done with the
+       If an empty string  is  matched,  the  next  match  is  done  with  the
        PCRE2_NOTEMPTY_ATSTART and PCRE2_ANCHORED flags set, in order to search
        for another, non-empty, match at the same point in the subject. If this
-       match fails, the start offset is advanced,  and  the  normal  match  is
-       retried.  This  imitates the way Perl handles such cases when using the
-       /g modifier or the split() function.  Normally,  the  start  offset  is
-       advanced  by  one  character,  but if the newline convention recognizes
-       CRLF as a newline, and the current character is CR followed by  LF,  an
+       match  fails,  the  start  offset  is advanced, and the normal match is
+       retried. This imitates the way Perl handles such cases when  using  the
+       /g  modifier  or  the  split()  function. Normally, the start offset is
+       advanced by one character, but if  the  newline  convention  recognizes
+       CRLF  as  a newline, and the current character is CR followed by LF, an
        advance of two characters occurs.
 
    Testing substring extraction functions
 
-       The  copy  and  get  modifiers  can  be  used  to  test  the pcre2_sub-
+       The copy  and  get  modifiers  can  be  used  to  test  the  pcre2_sub-
        string_copy_xxx() and pcre2_substring_get_xxx() functions.  They can be
-       given  more than once, and each can specify a group name or number, for
+       given more than once, and each can specify a group name or number,  for
        example:
 
           abcd\=copy=1,copy=3,get=G1
 
-       If the #subject command is used to set default copy and/or  get  lists,
-       these  can  be unset by specifying a negative number to cancel all num-
+       If  the  #subject command is used to set default copy and/or get lists,
+       these can be unset by specifying a negative number to cancel  all  num-
        bered groups and an empty name to cancel all named groups.
 
-       The getall modifier tests  pcre2_substring_list_get(),  which  extracts
+       The  getall  modifier  tests pcre2_substring_list_get(), which extracts
        all captured substrings.
 
-       If  the  subject line is successfully matched, the substrings extracted
-       by the convenience functions are output with  C,  G,  or  L  after  the
-       string  number  instead  of  a colon. This is in addition to the normal
-       full list. The string length (that is, the return from  the  extraction
+       If the subject line is successfully matched, the  substrings  extracted
+       by  the  convenience  functions  are  output  with C, G, or L after the
+       string number instead of a colon. This is in  addition  to  the  normal
+       full  list.  The string length (that is, the return from the extraction
        function) is given in parentheses after each substring, followed by the
        name when the extraction was by name.
 
    Testing the substitution function
 
-       If the replace modifier is  set,  the  pcre2_substitute()  function  is
-       called  instead of one of the matching functions. Note that replacement
-       strings cannot contain commas, because a comma signifies the end  of  a
+       If  the  replace  modifier  is  set, the pcre2_substitute() function is
+       called instead of one of the matching functions. Note that  replacement
+       strings  cannot  contain commas, because a comma signifies the end of a
        modifier. This is not thought to be an issue in a test program.
 
-       Unlike  subject strings, pcre2test does not process replacement strings
-       for escape sequences. In UTF mode, a replacement string is  checked  to
-       see  if it is a valid UTF-8 string. If so, it is correctly converted to
-       a UTF string of the appropriate code unit width. If it is not  a  valid
-       UTF-8  string, the individual code units are copied directly. This pro-
+       Unlike subject strings, pcre2test does not process replacement  strings
+       for  escape  sequences. In UTF mode, a replacement string is checked to
+       see if it is a valid UTF-8 string. If so, it is correctly converted  to
+       a  UTF  string of the appropriate code unit width. If it is not a valid
+       UTF-8 string, the individual code units are copied directly. This  pro-
        vides a means of passing an invalid UTF-8 string for testing purposes.
 
-       The following modifiers set options (in additional to the normal  match
+       The  following modifiers set options (in additional to the normal match
        options) for pcre2_substitute():
 
          global                      PCRE2_SUBSTITUTE_GLOBAL
@@ -1176,8 +1200,8 @@ SUBJECT MODIFIERS
          substitute_unset_empty      PCRE2_SUBSTITUTE_UNSET_EMPTY
 
 
-       After  a  successful  substitution, the modified string is output, pre-
-       ceded by the number of replacements. This may be zero if there were  no
+       After a successful substitution, the modified string  is  output,  pre-
+       ceded  by the number of replacements. This may be zero if there were no
        matches. Here is a simple example of a substitution test:
 
          /abc/replace=xxx
@@ -1186,12 +1210,12 @@ SUBJECT MODIFIERS
              =abc=abc=\=global
           2: =xxx=xxx=
 
-       Subject  and replacement strings should be kept relatively short (fewer
-       than 256 characters) for substitution tests, as fixed-size buffers  are
-       used.  To  make it easy to test for buffer overflow, if the replacement
-       string starts with a number in square brackets, that number  is  passed
-       to  pcre2_substitute()  as  the  size  of  the  output buffer, with the
-       replacement string starting at the next character. Here is  an  example
+       Subject and replacement strings should be kept relatively short  (fewer
+       than  256 characters) for substitution tests, as fixed-size buffers are
+       used. To make it easy to test for buffer overflow, if  the  replacement
+       string  starts  with a number in square brackets, that number is passed
+       to pcre2_substitute() as the  size  of  the  output  buffer,  with  the
+       replacement  string  starting at the next character. Here is an example
        that tests the edge case:
 
          /abc/
@@ -1200,11 +1224,11 @@ SUBJECT MODIFIERS
              123abc123\=replace=[9]XYZ
          Failed: error -47: no more memory
 
-       The    default    action    of    pcre2_substitute()   is   to   return
-       PCRE2_ERROR_NOMEMORY when the output buffer is too small.  However,  if
-       the  PCRE2_SUBSTITUTE_OVERFLOW_LENGTH  option is set (by using the sub-
-       stitute_overflow_length modifier), pcre2_substitute() continues  to  go
-       through  the  motions of matching and substituting, in order to compute
+       The   default   action   of    pcre2_substitute()    is    to    return
+       PCRE2_ERROR_NOMEMORY  when  the output buffer is too small. However, if
+       the PCRE2_SUBSTITUTE_OVERFLOW_LENGTH option is set (by using  the  sub-
+       stitute_overflow_length  modifier),  pcre2_substitute() continues to go
+       through the motions of matching and substituting, in order  to  compute
        the size of buffer that is required. When this happens, pcre2test shows
        the required buffer length (which includes space for the trailing zero)
        as part of the error message. For example:
@@ -1214,105 +1238,106 @@ SUBJECT MODIFIERS
          Failed: error -47: no more memory: 10 code units are needed
 
        A replacement string is ignored with POSIX and DFA matching. Specifying
-       partial  matching  provokes  an  error return ("bad option value") from
+       partial matching provokes an error return  ("bad  option  value")  from
        pcre2_substitute().
 
    Setting the JIT stack size
 
-       The jitstack modifier provides a way of setting the maximum stack  size
-       that  is  used  by the just-in-time optimization code. It is ignored if
+       The  jitstack modifier provides a way of setting the maximum stack size
+       that is used by the just-in-time optimization code. It  is  ignored  if
        JIT optimization is not being used. The value is a number of kilobytes.
-       Providing a stack that is larger than the default 32K is necessary only
-       for very complicated patterns.
+       Setting zero reverts to the default of 32K. Providing a stack  that  is
+       larger  than  the  default  is necessary only for very complicated pat-
+       terns. If jitstack is set non-zero on a subject line it  overrides  any
+       value that was set on the pattern.
 
    Setting heap, match, and depth limits
 
-       The heap_limit, match_limit, and depth_limit modifiers set  the  appro-
-       priate  limits  in the match context. These values are ignored when the
+       The  heap_limit,  match_limit, and depth_limit modifiers set the appro-
+       priate limits in the match context. These values are ignored  when  the
        find_limits modifier is specified.
 
    Finding minimum limits
 
-       If the find_limits modifier is present on  a  subject  line,  pcre2test
-       calls  the  relevant matching function several times, setting different
-       values   in   the    match    context    via    pcre2_set_heap_limit(),
-       pcre2_set_match_limit(),  or pcre2_set_depth_limit() until it finds the
-       minimum values for each parameter that allows  the  match  to  complete
+       If  the  find_limits  modifier  is present on a subject line, pcre2test
+       calls the relevant matching function several times,  setting  different
+       values    in    the    match    context   via   pcre2_set_heap_limit(),
+       pcre2_set_match_limit(), or pcre2_set_depth_limit() until it finds  the
+       minimum  values  for  each  parameter that allows the match to complete
        without error.
 
        If JIT is being used, only the match limit is relevant. If DFA matching
        is being used, only the depth limit is relevant.
 
-       The match_limit number is a measure of the amount of backtracking  that
-       takes  place,  and  learning  the minimum value 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
+       The  match_limit number is a measure of the amount of backtracking that
+       takes place, and learning the minimum value  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.
 
-       For non-DFA matching, the minimum depth_limit number is  a  measure  of
+       For  non-DFA  matching,  the minimum depth_limit number is a measure of
        how much nested backtracking happens (that is, how deeply the pattern's
-       tree is searched). In the case of DFA  matching,  depth_limit  controls
-       the  depth of recursive calls of the internal function that is used for
+       tree  is  searched).  In the case of DFA matching, depth_limit controls
+       the depth of recursive calls of the internal function that is used  for
        handling pattern recursion, lookaround assertions, and atomic groups.
 
    Showing MARK names
 
 
        The mark modifier causes the names from backtracking control verbs that
-       are  returned from calls to pcre2_match() to be displayed. If a mark is
-       returned for a match, non-match, or partial match, pcre2test shows  it.
-       For  a  match, it is on a line by itself, tagged with "MK:". Otherwise,
+       are returned from calls to pcre2_match() to be displayed. If a mark  is
+       returned  for a match, non-match, or partial match, pcre2test shows it.
+       For a match, it is on a line by itself, tagged with  "MK:".  Otherwise,
        it is added to the non-match message.
 
    Showing memory usage
 
-       The memory modifier causes pcre2test to log the sizes of all heap  mem-
-       ory   allocation  and  freeing  calls  that  occur  during  a  call  to
-       pcre2_match(). These occur only when a match requires a  bigger  vector
-       than  the  default  for  remembering backtracking points. In many cases
-       there will be no heap memory used and therefore no  additional  output.
-       No  heap  memory  is  allocated during matching with pcre2_dfa_match or
-       with JIT, so in those cases the memory modifier never has  any  effect.
+       The  memory modifier causes pcre2test to log the sizes of all heap mem-
+       ory  allocation  and  freeing  calls  that  occur  during  a  call   to
+       pcre2_match().  These  occur only when a match requires a bigger vector
+       than the default for remembering backtracking  points.  In  many  cases
+       there  will  be no heap memory used and therefore no additional output.
+       No heap memory is allocated during  matching  with  pcre2_dfa_match  or
+       with  JIT,  so in those cases the memory modifier never has any effect.
        For this modifier to work, the null_context modifier must not be set on
-       both the pattern and the subject, though it can be set on  one  or  the
+       both  the  pattern  and the subject, though it can be set on one or the
        other.
 
    Setting a starting offset
 
-       The  offset  modifier  sets  an  offset  in the subject string at which
+       The offset modifier sets an offset  in  the  subject  string  at  which
        matching starts. Its value is a number of code units, not characters.
 
    Setting an offset limit
 
-       The offset_limit modifier sets a limit for  unanchored  matches.  If  a
+       The  offset_limit  modifier  sets  a limit for unanchored matches. If a
        match cannot be found starting at or before this offset in the subject,
        a "no match" return is given. The data value is a number of code units,
-       not  characters. When this modifier is used, the use_offset_limit modi-
+       not characters. When this modifier is used, the use_offset_limit  modi-
        fier must have been set for the pattern; if not, an error is generated.
 
    Setting the size of the output vector
 
-       The ovector modifier applies only to  the  subject  line  in  which  it
-       appears,  though  of  course  it can also be used to set a default in a
-       #subject command. It specifies the number of pairs of offsets that  are
+       The  ovector  modifier  applies  only  to  the subject line in which it
+       appears, though of course it can also be used to set  a  default  in  a
+       #subject  command. It specifies the number of pairs of offsets that are
        available for storing matching information. The default is 15.
 
-       A  value of zero is useful when testing the POSIX API because it causes
+       A value of zero is useful when testing the POSIX API because it  causes
        regexec() to be called with a NULL capture vector. When not testing the
-       POSIX  API,  a  value  of  zero  is used to cause pcre2_match_data_cre-
-       ate_from_pattern() to be called, in order to create a  match  block  of
+       POSIX API, a value of  zero  is  used  to  cause  pcre2_match_data_cre-
+       ate_from_pattern()  to  be  called, in order to create a match block of
        exactly the right size for the pattern. (It is not possible to create a
-       match block with a zero-length ovector; there is always  at  least  one
+       match  block  with  a zero-length ovector; there is always at least one
        pair of offsets.)
 
    Passing the subject as zero-terminated
 
        By default, the subject string is passed to a native API matching func-
        tion with its correct length. In order to test the facility for passing
-       a  zero-terminated  string, the zero_terminate modifier is provided. It
-       causes the length to be passed as PCRE2_ZERO_TERMINATED. (When matching
-       via  the  POSIX  interface, this modifier has no effect, as there is no
-       facility for passing a length.)
+       a zero-terminated string, the zero_terminate modifier is  provided.  It
+       causes  the length to be passed as PCRE2_ZERO_TERMINATED. When matching
+       via the POSIX interface, this modifier is ignored, with a warning.
 
        When testing pcre2_substitute(), this modifier also has the  effect  of
        passing the replacement string as zero-terminated.
@@ -1513,8 +1538,8 @@ CALLOUTS
        position, which can happen if the callout is in a lookbehind assertion.
 
        Callouts numbered 255 are assumed to be automatic callouts, inserted as
-       a  result  of the /auto_callout pattern modifier. In this case, instead
-       of showing the callout number, the offset in the pattern, preceded by a
+       a result of the auto_callout 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]\*/auto_callout
@@ -1662,5 +1687,5 @@ AUTHOR
 
 REVISION
 
-       Last updated: 03 June 2017
+       Last updated: 16 June 2017
        Copyright (c) 1997-2017 University of Cambridge.