/[pcre]/code/trunk/doc/pcretest.txt
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revision 77 by nigel, Sat Feb 24 21:40:45 2007 UTC revision 567 by ph10, Sat Nov 6 17:10:00 2010 UTC
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1  PCRETEST(1)                                                        PCRETEST(1)  PCRETEST(1)                                                        PCRETEST(1)
2    
3    
   
4  NAME  NAME
5         pcretest - a program for testing Perl-compatible regular expressions.         pcretest - a program for testing Perl-compatible regular expressions.
6    
7    
8  SYNOPSIS  SYNOPSIS
9    
10         pcretest [-C] [-d] [-dfa] [-i] [-m] [-o osize] [-p] [-t] [source]         pcretest [options] [source] [destination]
             [destination]  
11    
12         pcretest  was written as a test program for the PCRE regular expression         pcretest  was written as a test program for the PCRE regular expression
13         library itself, but it can also be used for experimenting with  regular         library itself, but it can also be used for experimenting with  regular
# Line 20  SYNOPSIS Line 19  SYNOPSIS
19    
20  OPTIONS  OPTIONS
21    
22           -b        Behave as if each regex has the /B (show bytecode)  modifier;
23                     the internal form is output after compilation.
24    
25         -C        Output the version number of the PCRE library, and all avail-         -C        Output the version number of the PCRE library, and all avail-
26                   able   information  about  the  optional  features  that  are                   able  information  about  the  optional  features  that   are
27                   included, and then exit.                   included, and then exit.
28    
29         -d        Behave as if each regex has  the  /D  (debug)  modifier;  the         -d        Behave  as  if  each  regex  has the /D (debug) modifier; the
30                   internal form is output after compilation.                   internal form and information about the compiled  pattern  is
31                     output after compilation; -d is equivalent to -b -i.
32    
33         -dfa      Behave  as if each data line contains the \D escape sequence;         -dfa      Behave  as if each data line contains the \D escape sequence;
34                   this    causes    the    alternative    matching    function,                   this    causes    the    alternative    matching    function,
35                   pcre_dfa_exec(),   to   be   used  instead  of  the  standard                   pcre_dfa_exec(),   to   be   used  instead  of  the  standard
36                   pcre_exec() function (more detail is given below).                   pcre_exec() function (more detail is given below).
37    
38           -help     Output a brief summary these options and then exit.
39    
40         -i        Behave as if each regex  has  the  /I  modifier;  information         -i        Behave as if each regex  has  the  /I  modifier;  information
41                   about the compiled pattern is given after compilation.                   about the compiled pattern is given after compilation.
42    
43         -m        Output  the  size  of each compiled pattern after it has been         -M        Behave  as if each data line contains the \M escape sequence;
44                   compiled. This is equivalent to adding  /M  to  each  regular                   this causes PCRE to  discover  the  minimum  MATCH_LIMIT  and
45                   expression.   For  compatibility  with  earlier  versions  of                   MATCH_LIMIT_RECURSION settings by calling pcre_exec() repeat-
46                     edly with different limits.
47    
48           -m        Output the size of each compiled pattern after  it  has  been
49                     compiled.  This  is  equivalent  to adding /M to each regular
50                     expression.  For  compatibility  with  earlier  versions   of
51                   pcretest, -s is a synonym for -m.                   pcretest, -s is a synonym for -m.
52    
53         -o osize  Set the number of elements in the output vector that is  used         -o osize  Set  the number of elements in the output vector that is used
54                   when  calling  pcre_exec()  to be osize. The default value is                   when calling pcre_exec() or pcre_dfa_exec() to be osize.  The
55                   45, which is enough for 14 capturing subexpressions. The vec-                   default  value is 45, which is enough for 14 capturing subex-
56                   tor  size  can  be  changed  for individual matching calls by                   pressions  for  pcre_exec()  or  22  different  matches   for
57                   including \O in the data line (see below).                   pcre_dfa_exec().  The vector size can be changed for individ-
58                     ual matching calls by including \O  in  the  data  line  (see
59                     below).
60    
61         -p        Behave as if each regex has the /P modifier; the POSIX  wrap-         -p        Behave  as if each regex has the /P modifier; the POSIX wrap-
62                   per  API  is used to call PCRE. None of the other options has                   per API is used to call PCRE. None of the other  options  has
63                   any effect when -p is set.                   any effect when -p is set.
64    
65         -t        Run each compile, study, and match many times with  a  timer,         -q        Do  not output the version number of pcretest at the start of
66                   and  output resulting time per compile or match (in millisec-                   execution.
67                   onds). Do not set -m with -t, because you will then  get  the  
68                   size  output  a  zillion  times,  and the timing will be dis-         -S size   On Unix-like systems, set the size of the  runtime  stack  to
69                   torted.                   size megabytes.
70    
71           -t        Run  each  compile, study, and match many times with a timer,
72                     and output resulting time per compile or match (in  millisec-
73                     onds).  Do  not set -m with -t, because you will then get the
74                     size output a zillion times, and  the  timing  will  be  dis-
75                     torted.  You  can  control  the number of iterations that are
76                     used for timing by following -t with a number (as a  separate
77                     item on the command line). For example, "-t 1000" would iter-
78                     ate 1000 times. The default is to iterate 500000 times.
79    
80           -tm       This is like -t except that it times only the matching phase,
81                     not the compile or study phases.
82    
83    
84  DESCRIPTION  DESCRIPTION
85    
86         If pcretest is given two filename arguments, it reads  from  the  first         If  pcretest  is  given two filename arguments, it reads from the first
87         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
88         reads from that file and writes to stdout.  Otherwise,  it  reads  from         reads  from  that  file  and writes to stdout. Otherwise, it reads from
89         stdin  and  writes to stdout, and prompts for each line of input, using         stdin and writes to stdout, and prompts for each line of  input,  using
90         "re>" to prompt for regular expressions, and "data>" to prompt for data         "re>" to prompt for regular expressions, and "data>" to prompt for data
91         lines.         lines.
92    
93           When pcretest is built, a configuration  option  can  specify  that  it
94           should  be  linked  with the libreadline library. When this is done, if
95           the input is from a terminal, it is read using the readline() function.
96           This  provides line-editing and history facilities. The output from the
97           -help option states whether or not readline() will be used.
98    
99         The program handles any number of sets of input on a single input file.         The program handles any number of sets of input on a single input file.
100         Each set starts with a regular expression, and continues with any  num-         Each  set starts with a regular expression, and continues with any num-
101         ber of data lines to be matched against the pattern.         ber of data lines to be matched against the pattern.
102    
103         Each  data line is matched separately and independently. If you want to         Each data line is matched separately and independently. If you want  to
104         do multiple-line matches, you have to use the \n escape sequence  in  a         do multi-line matches, you have to use the \n escape sequence (or \r or
105         single  line  of  input  to  encode the newline characters. The maximum         \r\n, etc., depending on the newline setting) in a single line of input
106         length of data line is 30,000 characters.         to  encode  the  newline  sequences. There is no limit on the length of
107           data lines; the input buffer is automatically extended  if  it  is  too
108         An empty line signals the end of the data lines, at which point  a  new         small.
109         regular  expression is read. The regular expressions are given enclosed  
110         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
111           regular expression is read. The regular expressions are given  enclosed
112           in any non-alphanumeric delimiters other than backslash, for example:
113    
114           /(a|bc)x+yz/           /(a|bc)x+yz/
115    
116         White space before the initial delimiter is ignored. A regular  expres-         White  space before the initial delimiter is ignored. A regular expres-
117         sion  may be continued over several input lines, in which case the new-         sion may be continued over several input lines, in which case the  new-
118         line characters are included within it. It is possible to  include  the         line  characters  are included within it. It is possible to include the
119         delimiter within the pattern by escaping it, for example         delimiter within the pattern by escaping it, for example
120    
121           /abc\/def/           /abc\/def/
122    
123         If  you  do  so, the escape and the delimiter form part of the pattern,         If you do so, the escape and the delimiter form part  of  the  pattern,
124         but since delimiters are always non-alphanumeric, this does not  affect         but  since delimiters are always non-alphanumeric, this does not affect
125         its  interpretation.   If the terminating delimiter is immediately fol-         its interpretation.  If the terminating delimiter is  immediately  fol-
126         lowed by a backslash, for example,         lowed by a backslash, for example,
127    
128           /abc/\           /abc/\
129    
130         then a backslash is added to the end of the pattern. This  is  done  to         then  a  backslash  is added to the end of the pattern. This is done to
131         provide  a  way of testing the error condition that arises if a pattern         provide a way of testing the error condition that arises if  a  pattern
132         finishes with a backslash, because         finishes with a backslash, because
133    
134           /abc\/           /abc\/
135    
136         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/",
137         causing pcretest to read the next line as a continuation of the regular         causing pcretest to read the next line as a continuation of the regular
138         expression.         expression.
139    
140    
141  PATTERN MODIFIERS  PATTERN MODIFIERS
142    
143         A pattern may be followed by any number of modifiers, which are  mostly         A  pattern may be followed by any number of modifiers, which are mostly
144         single  characters.  Following  Perl usage, these are referred to below         single characters. Following Perl usage, these are  referred  to  below
145         as, for example, "the /i modifier", even though the  delimiter  of  the         as,  for  example,  "the /i modifier", even though the delimiter of the
146         pattern  need  not always be a slash, and no slash is used when writing         pattern need not always be a slash, and no slash is used  when  writing
147         modifiers. Whitespace may appear between the  final  pattern  delimiter         modifiers.  Whitespace  may  appear between the final pattern delimiter
148         and the first modifier, and between the modifiers themselves.         and the first modifier, and between the modifiers themselves.
149    
150         The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,         The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
151         PCRE_DOTALL, or PCRE_EXTENDED  options,  respectively,  when  pcre_com-         PCRE_DOTALL,  or  PCRE_EXTENDED  options,  respectively, when pcre_com-
152         pile()  is  called. These four modifier letters have the same effect as         pile() is called. These four modifier letters have the same  effect  as
153         they do in Perl. For example:         they do in Perl. For example:
154    
155           /caseless/i           /caseless/i
156    
157         The following table shows additional modifiers for setting PCRE options         The  following  table  shows additional modifiers for setting PCRE com-
158         that do not correspond to anything in Perl:         pile-time options that do not correspond to anything in Perl:
159    
160             /8              PCRE_UTF8
161             /?              PCRE_NO_UTF8_CHECK
162             /A              PCRE_ANCHORED
163             /C              PCRE_AUTO_CALLOUT
164             /E              PCRE_DOLLAR_ENDONLY
165             /f              PCRE_FIRSTLINE
166             /J              PCRE_DUPNAMES
167             /N              PCRE_NO_AUTO_CAPTURE
168             /U              PCRE_UNGREEDY
169             /W              PCRE_UCP
170             /X              PCRE_EXTRA
171             /<JS>           PCRE_JAVASCRIPT_COMPAT
172             /<cr>           PCRE_NEWLINE_CR
173             /<lf>           PCRE_NEWLINE_LF
174             /<crlf>         PCRE_NEWLINE_CRLF
175             /<anycrlf>      PCRE_NEWLINE_ANYCRLF
176             /<any>          PCRE_NEWLINE_ANY
177             /<bsr_anycrlf>  PCRE_BSR_ANYCRLF
178             /<bsr_unicode>  PCRE_BSR_UNICODE
179    
180           The modifiers that are enclosed in angle brackets are  literal  strings
181           as  shown,  including  the  angle  brackets,  but the letters can be in
182           either case. This example sets multiline matching with CRLF as the line
183           ending sequence:
184    
185             /^abc/m<crlf>
186    
187           As well as turning on the PCRE_UTF8 option, the /8 modifier also causes
188           any non-printing characters in output strings to be printed  using  the
189           \x{hh...}  notation  if they are valid UTF-8 sequences. Full details of
190           the PCRE options are given in the pcreapi documentation.
191    
192           /A    PCRE_ANCHORED     Finding all matches in a string
          /C    PCRE_AUTO_CALLOUT  
          /E    PCRE_DOLLAR_ENDONLY  
          /f    PCRE_FIRSTLINE  
          /N    PCRE_NO_AUTO_CAPTURE  
          /U    PCRE_UNGREEDY  
          /X    PCRE_EXTRA  
193    
194         Searching  for  all  possible matches within each subject string can be         Searching for all possible matches within each subject  string  can  be
195         requested by the /g or /G modifier. After  finding  a  match,  PCRE  is         requested  by  the  /g  or  /G modifier. After finding a match, PCRE is
196         called again to search the remainder of the subject string. The differ-         called again to search the remainder of the subject string. The differ-
197         ence between /g and /G is that the former uses the startoffset argument         ence between /g and /G is that the former uses the startoffset argument
198         to  pcre_exec()  to  start  searching  at a new point within the entire         to pcre_exec() to start searching at a  new  point  within  the  entire
199         string (which is in effect what Perl does), whereas the  latter  passes         string  (which  is in effect what Perl does), whereas the latter passes
200         over  a  shortened  substring.  This makes a difference to the matching         over a shortened substring. This makes a  difference  to  the  matching
201         process if the pattern begins with a lookbehind assertion (including \b         process if the pattern begins with a lookbehind assertion (including \b
202         or \B).         or \B).
203    
204         If  any  call  to  pcre_exec()  in a /g or /G sequence matches an empty         If any call to pcre_exec() in a /g or  /G  sequence  matches  an  empty
205         string, the next call is done with the PCRE_NOTEMPTY and  PCRE_ANCHORED         string,  the  next  call  is  done  with  the PCRE_NOTEMPTY_ATSTART and
206         flags  set in order to search for another, non-empty, match at the same         PCRE_ANCHORED flags set in order  to  search  for  another,  non-empty,
207         point.  If this second match fails, the start  offset  is  advanced  by         match  at  the same point. If this second match fails, the start offset
208         one,  and  the normal match is retried. This imitates the way Perl han-         is advanced, and the normal match is retried.  This  imitates  the  way
209         dles such cases when using the /g modifier or the split() function.         Perl handles such cases when using the /g modifier or the split() func-
210           tion. Normally, the start offset is advanced by one character,  but  if
211           the  newline  convention  recognizes CRLF as a newline, and the current
212           character is CR followed by LF, an advance of two is used.
213    
214       Other modifiers
215    
216         There are yet more modifiers for controlling the way pcretest operates.         There are yet more modifiers for controlling the way pcretest operates.
217    
218         The  /+ modifier requests that as well as outputting the substring that         The /+ modifier requests that as well as outputting the substring  that
219         matched the entire pattern, pcretest  should  in  addition  output  the         matched  the  entire  pattern,  pcretest  should in addition output the
220         remainder  of  the  subject  string. This is useful for tests where the         remainder of the subject string. This is useful  for  tests  where  the
221         subject contains multiple copies of the same substring.         subject contains multiple copies of the same substring.
222    
223         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-
224         example,         put a representation of the compiled byte code after compilation.  Nor-
225           mally  this  information contains length and offset values; however, if
226           /pattern/Lfr_FR         /Z is also present, this data is replaced by spaces. This is a  special
227           feature for use in the automatic test scripts; it ensures that the same
228         For this reason, it must be the last modifier. The given locale is set,         output is generated for different internal link sizes.
        pcre_maketables() is called to build a set of character tables for  the  
        locale,  and  this  is then passed to pcre_compile() when compiling the  
        regular expression. Without an /L  modifier,  NULL  is  passed  as  the  
        tables  pointer; that is, /L applies only to the expression on which it  
        appears.  
   
        The /I modifier requests that pcretest  output  information  about  the  
        compiled  pattern (whether it is anchored, has a fixed first character,  
        and so on). It does this by calling pcre_fullinfo() after  compiling  a  
        pattern.  If  the pattern is studied, the results of that are also out-  
        put.  
229    
230         The /D modifier is a PCRE debugging feature, which also assumes /I.  It         The /D modifier is a PCRE debugging feature, and is equivalent to  /BI,
231         causes  the  internal form of compiled regular expressions to be output         that is, both the /B and the /I modifiers.
        after compilation. If the pattern was studied, the information returned  
        is also output.  
232    
233         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
234         the compiled pattern that  contain  2-byte  and  4-byte  numbers.  This         the compiled pattern that  contain  2-byte  and  4-byte  numbers.  This
# Line 188  PATTERN MODIFIERS Line 238  PATTERN MODIFIERS
238         used, that is, when the /P pattern modifier is specified. See also  the         used, that is, when the /P pattern modifier is specified. See also  the
239         section about saving and reloading compiled patterns below.         section about saving and reloading compiled patterns below.
240    
241         The  /S  modifier causes pcre_study() to be called after the expression         The  /I  modifier  requests  that pcretest output information about the
242         has been compiled, and the results used when the expression is matched.         compiled pattern (whether it is anchored, has a fixed first  character,
243           and  so  on). It does this by calling pcre_fullinfo() after compiling a
244           pattern. If the pattern is studied, the results of that are  also  out-
245           put.
246    
247           The  /K modifier requests pcretest to show names from backtracking con-
248           trol verbs that are returned  from  calls  to  pcre_exec().  It  causes
249           pcretest  to create a pcre_extra block if one has not already been cre-
250           ated by a call to pcre_study(), and to set the PCRE_EXTRA_MARK flag and
251           the mark field within it, every time that pcre_exec() is called. If the
252           variable that the mark field points to is non-NULL for  a  match,  non-
253           match, or partial match, pcretest prints the string to which it points.
254           For a match, this is shown on a line by itself, tagged with "MK:".  For
255           a non-match it is added to the message.
256    
257           The  /L modifier must be followed directly by the name of a locale, for
258           example,
259    
260             /pattern/Lfr_FR
261    
262           For this reason, it must be the last modifier. The given locale is set,
263           pcre_maketables()  is called to build a set of character tables for the
264           locale, and this is then passed to pcre_compile()  when  compiling  the
265           regular  expression.  Without an /L (or /T) modifier, NULL is passed as
266           the tables pointer; that is, /L applies only to the expression on which
267           it appears.
268    
269         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-
270         piled pattern to be output.         piled pattern to be output.
271    
272         The /P modifier causes pcretest to call PCRE via the POSIX wrapper  API         The /S modifier causes pcre_study() to be called after  the  expression
273         rather  than  its  native  API.  When this is done, all other modifiers         has been compiled, and the results used when the expression is matched.
274         except /i, /m, and /+ are ignored. REG_ICASE is set if /i  is  present,  
275         and  REG_NEWLINE  is  set if /m is present. The wrapper functions force         The  /T  modifier  must be followed by a single digit. It causes a spe-
276         PCRE_DOLLAR_ENDONLY always, and PCRE_DOTALL unless REG_NEWLINE is  set.         cific set of built-in character tables to be passed to  pcre_compile().
277           It is used in the standard PCRE tests to check behaviour with different
278         The  /8 modifier causes pcretest to call PCRE with the PCRE_UTF8 option         character tables. The digit specifies the tables as follows:
279         set. This turns on support for UTF-8 character handling in  PCRE,  pro-  
280         vided  that  it  was  compiled with this support enabled. This modifier           0   the default ASCII tables, as distributed in
281         also causes any non-printing characters in output strings to be printed                 pcre_chartables.c.dist
282         using the \x{hh...} notation if they are valid UTF-8 sequences.           1   a set of tables defining ISO 8859 characters
283    
284         If  the  /?  modifier  is  used  with  /8,  it  causes pcretest to call         In table 1, some characters whose codes are greater than 128 are  iden-
285         pcre_compile() with the  PCRE_NO_UTF8_CHECK  option,  to  suppress  the         tified as letters, digits, spaces, etc.
286         checking of the string for UTF-8 validity.  
287       Using the POSIX wrapper API
288    
289           The  /P modifier causes pcretest to call PCRE via the POSIX wrapper API
290           rather than its native API. When /P is set, the following modifiers set
291           options for the regcomp() function:
292    
293             /i    REG_ICASE
294             /m    REG_NEWLINE
295             /N    REG_NOSUB
296             /s    REG_DOTALL     )
297             /U    REG_UNGREEDY   ) These options are not part of
298             /W    REG_UCP        )   the POSIX standard
299             /8    REG_UTF8       )
300    
301           The  /+  modifier  works  as  described  above. All other modifiers are
302           ignored.
303    
304    
305  DATA LINES  DATA LINES
306    
307         Before  each  data  line is passed to pcre_exec(), leading and trailing         Before each data line is passed to pcre_exec(),  leading  and  trailing
308         whitespace is removed, and it is then scanned for \  escapes.  Some  of         whitespace  is  removed,  and it is then scanned for \ escapes. Some of
309         these  are  pretty esoteric features, intended for checking out some of         these are pretty esoteric features, intended for checking out  some  of
310         the more complicated features of PCRE. If you are just  testing  "ordi-         the  more  complicated features of PCRE. If you are just testing "ordi-
311         nary"  regular  expressions,  you probably don't need any of these. The         nary" regular expressions, you probably don't need any  of  these.  The
312         following escapes are recognized:         following escapes are recognized:
313    
314           \a         alarm (= BEL)           \a         alarm (BEL, \x07)
315           \b         backspace           \b         backspace (\x08)
316           \e         escape           \e         escape (\x27)
317           \f         formfeed           \f         formfeed (\x0c)
318           \n         newline           \n         newline (\x0a)
319           \r         carriage return           \qdd       set the PCRE_MATCH_LIMIT limit to dd
320           \t         tab                        (any number of digits)
321           \v         vertical tab           \r         carriage return (\x0d)
322             \t         tab (\x09)
323             \v         vertical tab (\x0b)
324           \nnn       octal character (up to 3 octal digits)           \nnn       octal character (up to 3 octal digits)
325           \xhh       hexadecimal character (up to 2 hex digits)           \xhh       hexadecimal character (up to 2 hex digits)
326           \x{hh...}  hexadecimal character, any number of digits           \x{hh...}  hexadecimal character, any number of digits
327                        in UTF-8 mode                        in UTF-8 mode
328           \A         pass the PCRE_ANCHORED option to pcre_exec()           \A         pass the PCRE_ANCHORED option to pcre_exec()
329                          or pcre_dfa_exec()
330           \B         pass the PCRE_NOTBOL option to pcre_exec()           \B         pass the PCRE_NOTBOL option to pcre_exec()
331                          or pcre_dfa_exec()
332           \Cdd       call pcre_copy_substring() for substring dd           \Cdd       call pcre_copy_substring() for substring dd
333                        after a successful match (number less than 32)                        after a successful match (number less than 32)
334           \Cname     call pcre_copy_named_substring() for substring           \Cname     call pcre_copy_named_substring() for substring
# Line 257  DATA LINES Line 352  DATA LINES
352                        ated by next non-alphanumeric character)                        ated by next non-alphanumeric character)
353           \L         call pcre_get_substringlist() after a           \L         call pcre_get_substringlist() after a
354                        successful match                        successful match
355           \M         discover the minimum MATCH_LIMIT setting           \M         discover the minimum MATCH_LIMIT and
356                          MATCH_LIMIT_RECURSION settings
357           \N         pass the PCRE_NOTEMPTY option to pcre_exec()           \N         pass the PCRE_NOTEMPTY option to pcre_exec()
358                          or pcre_dfa_exec(); if used twice, pass the
359                          PCRE_NOTEMPTY_ATSTART option
360           \Odd       set the size of the output vector passed to           \Odd       set the size of the output vector passed to
361                        pcre_exec() to dd (any number of digits)                        pcre_exec() to dd (any number of digits)
362           \P         pass the PCRE_PARTIAL option to pcre_exec()           \P         pass the PCRE_PARTIAL_SOFT option to pcre_exec()
363                        or pcre_dfa_exec()                        or pcre_dfa_exec(); if used twice, pass the
364                          PCRE_PARTIAL_HARD option
365             \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
366                          (any number of digits)
367           \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()           \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
368           \S         output details of memory get/free calls during matching           \S         output details of memory get/free calls during matching
369             \Y         pass the PCRE_NO_START_OPTIMIZE option to pcre_exec()
370                          or pcre_dfa_exec()
371           \Z         pass the PCRE_NOTEOL option to pcre_exec()           \Z         pass the PCRE_NOTEOL option to pcre_exec()
372                          or pcre_dfa_exec()
373           \?         pass the PCRE_NO_UTF8_CHECK option to           \?         pass the PCRE_NO_UTF8_CHECK option to
374                        pcre_exec()                        pcre_exec() or pcre_dfa_exec()
375           \>dd       start the match at offset dd (any number of digits);           \>dd       start the match at offset dd (optional "-"; then
376                        this sets the startoffset argument for pcre_exec()                        any number of digits); this sets the startoffset
377                          argument for pcre_exec() or pcre_dfa_exec()
378         A backslash followed by anything else just escapes the  anything  else.           \<cr>      pass the PCRE_NEWLINE_CR option to pcre_exec()
379         If  the very last character is a backslash, it is ignored. This gives a                        or pcre_dfa_exec()
380         way of passing an empty line as data, since a real  empty  line  termi-           \<lf>      pass the PCRE_NEWLINE_LF option to pcre_exec()
381                          or pcre_dfa_exec()
382             \<crlf>    pass the PCRE_NEWLINE_CRLF option to pcre_exec()
383                          or pcre_dfa_exec()
384             \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre_exec()
385                          or pcre_dfa_exec()
386             \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
387                          or pcre_dfa_exec()
388    
389           The  escapes  that  specify  line ending sequences are literal strings,
390           exactly as shown. No more than one newline setting should be present in
391           any data line.
392    
393           A  backslash  followed by anything else just escapes the anything else.
394           If the very last character is a backslash, it is ignored. This gives  a
395           way  of  passing  an empty line as data, since a real empty line termi-
396         nates the data input.         nates the data input.
397    
398         If  \M  is present, pcretest calls pcre_exec() several times, with dif-         If \M is present, pcretest calls pcre_exec() several times,  with  dif-
399         ferent values in the match_limit field of the  pcre_extra  data  struc-         ferent  values  in  the match_limit and match_limit_recursion fields of
400         ture,  until it finds the minimum number that is needed for pcre_exec()         the pcre_extra data structure, until it finds the minimum  numbers  for
401         to complete. This number is a measure of the amount  of  recursion  and         each parameter that allow pcre_exec() to complete. The match_limit num-
402         backtracking  that takes place, and checking it out can be instructive.         ber is a measure of the amount of backtracking that  takes  place,  and
403         For most simple matches, the number is quite small,  but  for  patterns         checking it out can be instructive. For most simple matches, the number
404         with  very large numbers of matching possibilities, it can become large         is quite small, but for patterns with very large  numbers  of  matching
405         very quickly with increasing length of subject string.         possibilities,  it can become large very quickly with increasing length
406           of subject string. The match_limit_recursion number is a measure of how
407           much  stack  (or,  if  PCRE is compiled with NO_RECURSE, how much heap)
408           memory is needed to complete the match attempt.
409    
410         When \O is used, the value specified may be higher or  lower  than  the         When \O is used, the value specified may be higher or  lower  than  the
411         size set by the -O command line option (or defaulted to 45); \O applies         size set by the -O command line option (or defaulted to 45); \O applies
412         only to the call of pcre_exec() for the line in which it appears.         only to the call of pcre_exec() for the line in which it appears.
413    
414         If the /P modifier was present on the pattern, causing the POSIX  wrap-         If the /P modifier was present on the pattern, causing the POSIX  wrap-
415         per  API to be used, only \B and \Z have any effect, causing REG_NOTBOL         per  API  to  be  used, the only option-setting sequences that have any
416         and REG_NOTEOL to be passed to regexec() respectively.         effect are \B,  \N,  and  \Z,  causing  REG_NOTBOL,  REG_NOTEMPTY,  and
417           REG_NOTEOL, respectively, to be passed to regexec().
418         The use of \x{hh...} to represent UTF-8 characters is not dependent  on  
419         the  use  of  the  /8 modifier on the pattern. It is recognized always.         The  use of \x{hh...} to represent UTF-8 characters is not dependent on
420         There may be any number of hexadecimal digits inside  the  braces.  The         the use of the /8 modifier on the pattern.  It  is  recognized  always.
421         result  is from one to six bytes, encoded according to the UTF-8 rules.         There  may  be  any number of hexadecimal digits inside the braces. The
422           result is from one to six bytes,  encoded  according  to  the  original
423           UTF-8  rules  of  RFC  2279.  This  allows for values in the range 0 to
424           0x7FFFFFFF. Note that not all of those are valid Unicode  code  points,
425           or  indeed  valid  UTF-8 characters according to the later rules in RFC
426           3629.
427    
428    
429  THE ALTERNATIVE MATCHING FUNCTION  THE ALTERNATIVE MATCHING FUNCTION
# Line 321  DEFAULT OUTPUT FROM PCRETEST Line 448  DEFAULT OUTPUT FROM PCRETEST
448    
449         When a match succeeds, pcretest outputs the list of captured substrings         When a match succeeds, pcretest outputs the list of captured substrings
450         that pcre_exec() returns, starting with number 0 for  the  string  that         that pcre_exec() returns, starting with number 0 for  the  string  that
451         matched the whole pattern. Otherwise, it outputs "No match" or "Partial         matched  the  whole  pattern. Otherwise, it outputs "No match" when the
452         match" when pcre_exec() returns PCRE_ERROR_NOMATCH  or  PCRE_ERROR_PAR-         return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-
453         TIAL,  respectively, and otherwise the PCRE negative error number. Here         tially  matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL.
454         is an example of an interactive pcretest run.         (Note that this is the entire substring that was inspected  during  the
455           partial  match; it may include characters before the actual match start
456           if a lookbehind assertion, \K, \b, or \B was involved.) For  any  other
457           returns,  it outputs the PCRE negative error number. Here is an example
458           of an interactive pcretest run.
459    
460           $ pcretest           $ pcretest
461           PCRE version 5.00 07-Sep-2004           PCRE version 7.0 30-Nov-2006
462    
463             re> /^abc(\d+)/             re> /^abc(\d+)/
464           data> abc123           data> abc123
# Line 336  DEFAULT OUTPUT FROM PCRETEST Line 467  DEFAULT OUTPUT FROM PCRETEST
467           data> xyz           data> xyz
468           No match           No match
469    
470         If the strings contain any non-printing characters, they are output  as         Note that unset capturing substrings that are not followed by one  that
471         \0x  escapes,  or  as \x{...} escapes if the /8 modifier was present on         is  set are not returned by pcre_exec(), and are not shown by pcretest.
472         the pattern. If the pattern has the /+ modifier, the  output  for  sub-         In the following example, there are two capturing substrings, but  when
473         string  0 is followed by the the rest of the subject string, identified         the  first  data  line  is  matched, the second, unset substring is not
474         by "0+" like this:         shown. An "internal" unset substring is shown as "<unset>", as for  the
475           second data line.
476    
477               re> /(a)|(b)/
478             data> a
479              0: a
480              1: a
481             data> b
482              0: b
483              1: <unset>
484              2: b
485    
486           If  the strings contain any non-printing characters, they are output as
487           \0x escapes, or as \x{...} escapes if the /8 modifier  was  present  on
488           the  pattern.  See below for the definition of non-printing characters.
489           If the pattern has the /+ modifier, the output for substring 0 is  fol-
490           lowed  by  the  the rest of the subject string, identified by "0+" like
491           this:
492    
493             re> /cat/+             re> /cat/+
494           data> cataract           data> cataract
# Line 368  DEFAULT OUTPUT FROM PCRETEST Line 516  DEFAULT OUTPUT FROM PCRETEST
516         (that  is,  the return from the extraction function) is given in paren-         (that  is,  the return from the extraction function) is given in paren-
517         theses after each string for \C and \G.         theses after each string for \C and \G.
518    
519         Note that while patterns can be continued over several lines  (a  plain         Note that whereas patterns can be continued over several lines (a plain
520         ">" prompt is used for continuations), data lines may not. However new-         ">" prompt is used for continuations), data lines may not. However new-
521         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,
522           etc., depending on the newline sequence setting).
523    
524    
525  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION  OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
526    
527         When the alternative matching function, pcre_dfa_exec(),  is  used  (by         When  the  alternative  matching function, pcre_dfa_exec(), is used (by
528         means  of  the \D escape sequence or the -dfa command line option), the         means of the \D escape sequence or the -dfa command line  option),  the
529         output consists of a list of all the matches that start  at  the  first         output  consists  of  a list of all the matches that start at the first
530         point in the subject where there is at least one match. For example:         point in the subject where there is at least one match. For example:
531    
532             re> /(tang|tangerine|tan)/             re> /(tang|tangerine|tan)/
# Line 386  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 535  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
535            1: tang            1: tang
536            2: tan            2: tan
537    
538         (Using  the  normal  matching function on this data finds only "tang".)         (Using the normal matching function on this data  finds  only  "tang".)
539         The longest matching string is always given first (and numbered  zero).         The  longest matching string is always given first (and numbered zero).
540           After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
541           lowed  by  the  partially  matching  substring.  (Note that this is the
542           entire substring that was inspected during the partial  match;  it  may
543           include characters before the actual match start if a lookbehind asser-
544           tion, \K, \b, or \B was involved.)
545    
546         If  /gP  is  present  on  the  pattern,  the search for further matches         If /g is present on the pattern, the search for further matches resumes
547         resumes at the end of the longest match. For example:         at the end of the longest match. For example:
548    
549             re> /(tang|tangerine|tan)/g             re> /(tang|tangerine|tan)/g
550           data> yellow tangerine and tangy sultana\D           data> yellow tangerine and tangy sultana\D
# Line 401  OUTPUT FROM THE ALTERNATIVE MATCHING FUN Line 555  OUTPUT FROM THE ALTERNATIVE MATCHING FUN
555            1: tan            1: tan
556            0: tan            0: tan
557    
558         Since the matching function does not  support  substring  capture,  the         Since  the  matching  function  does not support substring capture, the
559         escape  sequences  that  are concerned with captured substrings are not         escape sequences that are concerned with captured  substrings  are  not
560         relevant.         relevant.
561    
562    
563  RESTARTING AFTER A PARTIAL MATCH  RESTARTING AFTER A PARTIAL MATCH
564    
565         When the alternative matching function has given the PCRE_ERROR_PARTIAL         When the alternative matching function has given the PCRE_ERROR_PARTIAL
566         return,  indicating that the subject partially matched the pattern, you         return, indicating that the subject partially matched the pattern,  you
567         can restart the match with additional subject data by means of  the  \R         can  restart  the match with additional subject data by means of the \R
568         escape sequence. For example:         escape sequence. For example:
569    
570             re> /^?(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)$/             re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
571           data> 23ja\P\D           data> 23ja\P\D
572           Partial match: 23ja           Partial match: 23ja
573           data> n05\R\D           data> n05\R\D
574            0: n05            0: n05
575    
576         For  further  information  about  partial matching, see the pcrepartial         For further information about partial  matching,  see  the  pcrepartial
577         documentation.         documentation.
578    
579    
580  CALLOUTS  CALLOUTS
581    
582         If the pattern contains any callout requests, pcretest's callout  func-         If  the pattern contains any callout requests, pcretest's callout func-
583         tion  is  called  during  matching. This works with both matching func-         tion is called during matching. This works  with  both  matching  func-
584         tions. By default, the called function displays the callout number, the         tions. By default, the called function displays the callout number, the
585         start  and  current  positions in the text at the callout time, and the         start and current positions in the text at the callout  time,  and  the
586         next pattern item to be tested. For example, the output         next pattern item to be tested. For example, the output
587    
588           --->pqrabcdef           --->pqrabcdef
589             0    ^  ^     \d             0    ^  ^     \d
590    
591         indicates that callout number 0 occurred for a match  attempt  starting         indicates  that  callout number 0 occurred for a match attempt starting
592         at  the fourth character of the subject string, when the pointer was at         at the fourth character of the subject string, when the pointer was  at
593         the seventh character of the data, and when the next pattern  item  was         the  seventh  character of the data, and when the next pattern item was
594         \d.  Just  one  circumflex is output if the start and current positions         \d. Just one circumflex is output if the start  and  current  positions
595         are the same.         are the same.
596    
597         Callouts numbered 255 are assumed to be automatic callouts, inserted as         Callouts numbered 255 are assumed to be automatic callouts, inserted as
598         a  result  of the /C pattern modifier. In this case, instead of showing         a result of the /C pattern modifier. In this case, instead  of  showing
599         the callout number, the offset in the pattern, preceded by a  plus,  is         the  callout  number, the offset in the pattern, preceded by a plus, is
600         output. For example:         output. For example:
601    
602             re> /\d?[A-E]\*/C             re> /\d?[A-E]\*/C
# Line 454  CALLOUTS Line 608  CALLOUTS
608           +10 ^ ^           +10 ^ ^
609            0: E*            0: E*
610    
611         The  callout  function  in pcretest returns zero (carry on matching) by         The callout function in pcretest returns zero (carry  on  matching)  by
612         default, but you can use a \C item in a data line (as described  above)         default,  but you can use a \C item in a data line (as described above)
613         to change this.         to change this.
614    
615         Inserting  callouts can be helpful when using pcretest to check compli-         Inserting callouts can be helpful when using pcretest to check  compli-
616         cated regular expressions. For further information about callouts,  see         cated  regular expressions. For further information about callouts, see
617         the pcrecallout documentation.         the pcrecallout documentation.
618    
619    
620    NON-PRINTING CHARACTERS
621    
622           When pcretest is outputting text in the compiled version of a  pattern,
623           bytes  other  than 32-126 are always treated as non-printing characters
624           are are therefore shown as hex escapes.
625    
626           When pcretest is outputting text that is a matched part  of  a  subject
627           string,  it behaves in the same way, unless a different locale has been
628           set for the  pattern  (using  the  /L  modifier).  In  this  case,  the
629           isprint() function to distinguish printing and non-printing characters.
630    
631    
632  SAVING AND RELOADING COMPILED PATTERNS  SAVING AND RELOADING COMPILED PATTERNS
633    
634         The  facilities  described  in  this section are not available when the         The  facilities  described  in  this section are not available when the
# Line 519  SAVING AND RELOADING COMPILED PATTERNS Line 685  SAVING AND RELOADING COMPILED PATTERNS
685         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.
686    
687    
688    SEE ALSO
689    
690           pcre(3), pcreapi(3), pcrecallout(3),  pcrematching(3),  pcrepartial(d),
691           pcrepattern(3), pcreprecompile(3).
692    
693    
694  AUTHOR  AUTHOR
695    
696         Philip Hazel         Philip Hazel
697         University Computing Service,         University Computing Service
698         Cambridge CB2 3QG, England.         Cambridge CB2 3QH, England.
699    
700    
701    REVISION
702    
703  Last updated: 28 February 2005         Last updated: 06 November 2010
704  Copyright (c) 1997-2005 University of Cambridge.         Copyright (c) 1997-2010 University of Cambridge.

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