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1    PCRETEST(1)                                                        PCRETEST(1)
2    
3    
4  NAME  NAME
5       pcretest - a program  for  testing  Perl-compatible  regular         pcretest - a program for testing Perl-compatible regular expressions.
      expressions.  
6    
7    
8  SYNOPSIS  SYNOPSIS
      pcretest [-d] [-i] [-m] [-o osize] [-p] [-t] [source]  [des-  
      tination]  
9    
10       pcretest was written as a test program for the PCRE  regular         pcretest [options] [input file [output file]]
11       expression  library  itself,  but  it  can  also be used for  
12       experimenting  with  regular  expressions.   This   document         pcretest  was written as a test program for the PCRE regular expression
13       describes  the  features of the test program; for details of         library itself, but it can also be used for experimenting with  regular
14       the regular  expressions  themselves,  see  the  pcrepattern         expressions.  This document describes the features of the test program;
15       documentation.  For details of PCRE and its options, see the         for details of the regular expressions themselves, see the  pcrepattern
16       pcreapi documentation.         documentation. For details of the PCRE library function calls and their
17           options, see the pcreapi documentation. The input  for  pcretest  is  a
18           sequence  of  regular expression patterns and strings to be matched, as
19  OPTIONS         described below. The output shows the result of each match. Options  on
20           the command line and the patterns control PCRE options and exactly what
21           is output.
22       -C        Output the version number of the PCRE library, and  
23                 all   available  information  about  the  optional  
24                 features that are included, and then exit.  COMMAND LINE OPTIONS
25    
26       -d        Behave as if each regex had the /D  modifier  (see         -b        Behave as if each pattern has the /B (show byte  code)  modi-
27                 below); the internal form is output after compila-                   fier; the internal form is output after compilation.
28                 tion.  
29           -C        Output the version number of the PCRE library, and all avail-
30       -i        Behave as if  each  regex  had  the  /I  modifier;                   able  information  about  the  optional  features  that   are
31                 information  about  the  compiled pattern is given                   included, and then exit.
32                 after compilation.  
33           -d        Behave  as  if  each pattern has the /D (debug) modifier; the
34       -m        Output the size of each compiled pattern after  it                   internal form and information about the compiled  pattern  is
35                 has been compiled. This is equivalent to adding /M                   output after compilation; -d is equivalent to -b -i.
36                 to each regular expression. For compatibility with  
37                 earlier  versions of pcretest, -s is a synonym for         -dfa      Behave  as if each data line contains the \D escape sequence;
38                 -m.                   this    causes    the    alternative    matching    function,
39                     pcre_dfa_exec(),   to   be   used  instead  of  the  standard
40       -o osize  Set the number of elements in  the  output  vector                   pcre_exec() function (more detail is given below).
41                 that  is  used  when calling PCRE to be osize. The  
42                 default value is 45, which is enough for  14  cap-         -help     Output a brief summary these options and then exit.
43                 turing  subexpressions.  The  vector  size  can be  
44                 changed for individual matching calls by including         -i        Behave as if each pattern has the  /I  modifier;  information
45                 \O in the data line (see below).                   about the compiled pattern is given after compilation.
46    
47       -p        Behave as if each regex has /P modifier; the POSIX         -M        Behave  as if each data line contains the \M escape sequence;
48                 wrapper  API  is  used  to  call PCRE. None of the                   this causes PCRE to  discover  the  minimum  MATCH_LIMIT  and
49                 other options has any effect when -p is set.                   MATCH_LIMIT_RECURSION settings by calling pcre_exec() repeat-
50                     edly with different limits.
51       -t        Run each compile, study, and match many times with  
52                 a  timer, and output resulting time per compile or         -m        Output the size of each compiled pattern after  it  has  been
53                 match (in milliseconds). Do not set  -t  with  -m,                   compiled.  This  is  equivalent  to adding /M to each regular
54                 because  you  will  then get the size output 20000                   expression.
55                 times and the timing will be distorted.  
56           -o osize  Set the number of elements in the output vector that is  used
57                     when  calling pcre_exec() or pcre_dfa_exec() to be osize. The
58                     default value is 45, which is enough for 14 capturing  subex-
59                     pressions   for  pcre_exec()  or  22  different  matches  for
60                     pcre_dfa_exec(). The vector size can be changed for  individ-
61                     ual  matching  calls  by  including  \O in the data line (see
62                     below).
63    
64           -p        Behave as if each pattern has  the  /P  modifier;  the  POSIX
65                     wrapper  API  is used to call PCRE. None of the other options
66                     has any effect when -p is set.
67    
68           -q        Do not output the version number of pcretest at the start  of
69                     execution.
70    
71           -S size   On  Unix-like  systems, set the size of the run-time stack to
72                     size megabytes.
73    
74           -s or -s+ Behave as if each pattern  has  the  /S  modifier;  in  other
75                     words,  force each pattern to be studied. If -s+ is used, the
76                     PCRE_STUDY_JIT_COMPILE flag is passed to pcre_study(),  caus-
77                     ing  just-in-time  optimization  to be set up if it is avail-
78                     able. If the  /I  or  /D  option  is  present  on  a  pattern
79                     (requesting  output  about the compiled pattern), information
80                     about the result of studying is not included when studying is
81                     caused  only  by  -s  and neither -i nor -d is present on the
82                     command line. This behaviour means that the output from tests
83                     that  are run with and without -s should be identical, except
84                     when options that output information about the actual running
85                     of  a  match are set. The -M, -t, and -tm options, which give
86                     information about resources used, are likely to produce  dif-
87                     ferent  output with and without -s. Output may also differ if
88                     the /C option is present on an individual pattern. This  uses
89                     callouts  to  trace the the matching process, and this may be
90                     different between studied and non-studied  patterns.  If  the
91                     pattern contains (*MARK) items there may also be differences,
92                     for the same reason. The -s command line option can be  over-
93                     ridden  for  specific  patterns  that should never be studied
94                     (see the /S pattern modifier below).
95    
96           -t        Run each compile, study, and match many times with  a  timer,
97                     and  output resulting time per compile or match (in millisec-
98                     onds). Do not set -m with -t, because you will then  get  the
99                     size  output  a  zillion  times,  and the timing will be dis-
100                     torted. You can control the number  of  iterations  that  are
101                     used  for timing by following -t with a number (as a separate
102                     item on the command line). For example, "-t 1000" would iter-
103                     ate 1000 times. The default is to iterate 500000 times.
104    
105           -tm       This is like -t except that it times only the matching phase,
106                     not the compile or study phases.
107    
108    
109  DESCRIPTION  DESCRIPTION
110    
111       If pcretest is given two filename arguments, it  reads  from         If pcretest is given two filename arguments, it reads  from  the  first
112       the  first and writes to the second. If it is given only one         and writes to the second. If it is given only one filename argument, it
113       filename argument, it reads from that  file  and  writes  to         reads from that file and writes to stdout.  Otherwise,  it  reads  from
114       stdout. Otherwise, it reads from stdin and writes to stdout,         stdin  and  writes to stdout, and prompts for each line of input, using
115       and prompts for each line of input, using  "re>"  to  prompt         "re>" to prompt for regular expressions, and "data>" to prompt for data
116       for  regular  expressions,  and  "data>"  to prompt for data         lines.
117       lines.  
118           When  pcretest  is  built,  a  configuration option can specify that it
119       The program handles any number of sets of input on a  single         should be linked with the libreadline library. When this  is  done,  if
120       input  file.  Each set starts with a regular expression, and         the input is from a terminal, it is read using the readline() function.
121       continues with any  number  of  data  lines  to  be  matched         This provides line-editing and history facilities. The output from  the
122       against the pattern.         -help option states whether or not readline() will be used.
123    
124       Each line is matched separately and  independently.  If  you         The program handles any number of sets of input on a single input file.
125       want  to  do  multiple-line  matches, you have to use the \n         Each set starts with a regular expression, and continues with any  num-
126       escape sequence in a single line of input to encode the new-         ber of data lines to be matched against the pattern.
127       line  characters.  The maximum length of data line is 30,000  
128       characters.         Each  data line is matched separately and independently. If you want to
129           do multi-line matches, you have to use the \n escape sequence (or \r or
130       An empty line signals the end of the data  lines,  at  which         \r\n, etc., depending on the newline setting) in a single line of input
131       point  a new regular expression is read. The regular expres-         to encode the newline sequences. There is no limit  on  the  length  of
132       sions are given enclosed in  any  non-alphameric  delimiters         data  lines;  the  input  buffer is automatically extended if it is too
133       other than backslash, for example         small.
134    
135         /(a|bc)x+yz/         An empty line signals the end of the data lines, at which point  a  new
136           regular  expression is read. The regular expressions are given enclosed
137       White space before the initial delimiter is ignored. A regu-         in any non-alphanumeric delimiters other than backslash, for example:
138       lar expression may be continued over several input lines, in  
139       which case the newline characters are included within it. It           /(a|bc)x+yz/
140       is  possible  to include the delimiter within the pattern by  
141       escaping it, for example         White space before the initial delimiter is ignored. A regular  expres-
142           sion  may be continued over several input lines, in which case the new-
143         /abc\/def/         line characters are included within it. It is possible to  include  the
144           delimiter within the pattern by escaping it, for example
145       If you do so, the escape and the delimiter form part of  the  
146       pattern,  but  since  delimiters  are always non-alphameric,           /abc\/def/
147       this does not affect its interpretation.  If the terminating  
148       delimiter  is immediately followed by a backslash, for exam-         If  you  do  so, the escape and the delimiter form part of the pattern,
149       ple,         but since delimiters are always non-alphanumeric, this does not  affect
150           its  interpretation.   If the terminating delimiter is immediately fol-
151         /abc/\         lowed by a backslash, for example,
152    
153       then a backslash is added to the end of the pattern. This is           /abc/\
154       done  to  provide  a way of testing the error condition that  
155       arises if a pattern finishes with a backslash, because         then a backslash is added to the end of the pattern. This  is  done  to
156           provide  a  way of testing the error condition that arises if a pattern
157         /abc\/         finishes with a backslash, because
158    
159       is interpreted as the first line of a  pattern  that  starts           /abc\/
160       with  "abc/",  causing  pcretest  to read the next line as a  
161       continuation of the regular expression.         is interpreted as the first line of a pattern that starts with  "abc/",
162           causing pcretest to read the next line as a continuation of the regular
163           expression.
164    
165    
166  PATTERN MODIFIERS  PATTERN MODIFIERS
167    
168       The pattern may be followed by i, m, s,  or  x  to  set  the         A pattern may be followed by any number of modifiers, which are  mostly
169       PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED         single  characters.  Following  Perl usage, these are referred to below
170       options, respectively. For example:         as, for example, "the /i modifier", even though the  delimiter  of  the
171           pattern  need  not always be a slash, and no slash is used when writing
172         /caseless/i         modifiers. White space may appear between the final  pattern  delimiter
173           and the first modifier, and between the modifiers themselves.
174       These modifier letters have the same effect as  they  do  in  
175       Perl.  There  are  others  that set PCRE options that do not         The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, PCRE_MULTILINE,
176       correspond to anything in Perl:  /A, /E, /N, /U, and /X  set         PCRE_DOTALL, or PCRE_EXTENDED  options,  respectively,  when  pcre_com-
177       PCRE_ANCHORED,   PCRE_DOLLAR_ENDONLY,  PCRE_NO_AUTO_CAPTURE,         pile()  is  called. These four modifier letters have the same effect as
178       PCRE_UNGREEDY, and PCRE_EXTRA respectively.         they do in Perl. For example:
179    
180       Searching for  all  possible  matches  within  each  subject           /caseless/i
181       string  can  be  requested  by  the /g or /G modifier. After  
182       finding  a  match,  PCRE  is  called  again  to  search  the         The following table shows additional modifiers for  setting  PCRE  com-
183       remainder  of  the subject string. The difference between /g         pile-time options that do not correspond to anything in Perl:
184       and /G is that the former uses the startoffset  argument  to  
185       pcre_exec()  to  start  searching  at a new point within the           /8              PCRE_UTF8
186       entire string (which is in effect what Perl  does),  whereas           /?              PCRE_NO_UTF8_CHECK
187       the  latter  passes over a shortened substring. This makes a           /A              PCRE_ANCHORED
188       difference to the matching process  if  the  pattern  begins           /C              PCRE_AUTO_CALLOUT
189       with a lookbehind assertion (including \b or \B).           /E              PCRE_DOLLAR_ENDONLY
190             /f              PCRE_FIRSTLINE
191       If any call to pcre_exec() in a /g or /G sequence matches an           /J              PCRE_DUPNAMES
192       empty  string,  the next call is done with the PCRE_NOTEMPTY           /N              PCRE_NO_AUTO_CAPTURE
193       and PCRE_ANCHORED flags set in order to search for  another,           /U              PCRE_UNGREEDY
194       non-empty,  match  at  the same point.  If this second match           /W              PCRE_UCP
195       fails, the start offset is advanced by one, and  the  normal           /X              PCRE_EXTRA
196       match  is  retried.  This imitates the way Perl handles such           /Y              PCRE_NO_START_OPTIMIZE
197       cases when using the /g modifier or the split() function.           /<JS>           PCRE_JAVASCRIPT_COMPAT
198             /<cr>           PCRE_NEWLINE_CR
199       There are a number of other modifiers  for  controlling  the           /<lf>           PCRE_NEWLINE_LF
200       way pcretest operates.           /<crlf>         PCRE_NEWLINE_CRLF
201             /<anycrlf>      PCRE_NEWLINE_ANYCRLF
202       The /+ modifier requests that as well as outputting the sub-           /<any>          PCRE_NEWLINE_ANY
203       string  that  matched the entire pattern, pcretest should in           /<bsr_anycrlf>  PCRE_BSR_ANYCRLF
204       addition output the remainder of the subject string. This is           /<bsr_unicode>  PCRE_BSR_UNICODE
205       useful  for tests where the subject contains multiple copies  
206       of the same substring.         The  modifiers  that are enclosed in angle brackets are literal strings
207           as shown, including the angle brackets, but the letters within  can  be
208       The /L modifier must be followed directly by the name  of  a         in  either case.  This example sets multiline matching with CRLF as the
209       locale, for example,         line ending sequence:
210    
211         /pattern/Lfr           /^abc/m<CRLF>
212    
213       For this reason, it must be the last  modifier  letter.  The         As well as turning on the PCRE_UTF8 option, the /8 modifier also causes
214       given  locale is set, pcre_maketables() is called to build a         any  non-printing  characters in output strings to be printed using the
215       set of character tables for the locale,  and  this  is  then         \x{hh...} notation if they are valid UTF-8 sequences. Full  details  of
216       passed  to pcre_compile() when compiling the regular expres-         the PCRE options are given in the pcreapi documentation.
217       sion. Without an /L modifier, NULL is passed as  the  tables  
218       pointer; that is, /L applies only to the expression on which     Finding all matches in a string
219       it appears.  
220           Searching  for  all  possible matches within each subject string can be
221       The /I modifier requests that  pcretest  output  information         requested by the /g or /G modifier. After  finding  a  match,  PCRE  is
222       about the compiled expression (whether it is anchored, has a         called again to search the remainder of the subject string. The differ-
223       fixed first character, and so on). It does this  by  calling         ence between /g and /G is that the former uses the startoffset argument
224       pcre_fullinfo()  after  compiling an expression, and output-         to  pcre_exec()  to  start  searching  at a new point within the entire
225       ting the information it gets back. If the  pattern  is  stu-         string (which is in effect what Perl does), whereas the  latter  passes
226       died, the results of that are also output.         over  a  shortened  substring.  This makes a difference to the matching
227           process if the pattern begins with a lookbehind assertion (including \b
228       The /D modifier is a  PCRE  debugging  feature,  which  also         or \B).
229       assumes /I.  It causes the internal form of compiled regular  
230       expressions to be output after compilation. If  the  pattern         If  any  call  to  pcre_exec()  in a /g or /G sequence matches an empty
231       was studied, the information returned is also output.         string, the next  call  is  done  with  the  PCRE_NOTEMPTY_ATSTART  and
232           PCRE_ANCHORED  flags  set  in  order  to search for another, non-empty,
233       The /S modifier causes pcre_study() to be called  after  the         match at the same point. If this second match fails, the  start  offset
234       expression  has been compiled, and the results used when the         is  advanced,  and  the  normal match is retried. This imitates the way
235       expression is matched.         Perl handles such cases when using the /g modifier or the split() func-
236           tion.  Normally,  the start offset is advanced by one character, but if
237       The /M modifier causes the size of memory block used to hold         the newline convention recognizes CRLF as a newline,  and  the  current
238       the compiled pattern to be output.         character is CR followed by LF, an advance of two is used.
239    
240       The /P modifier causes pcretest to call PCRE via  the  POSIX     Other modifiers
241       wrapper  API  rather than its native API. When this is done,  
242       all other modifiers except  /i,  /m,  and  /+  are  ignored.         There are yet more modifiers for controlling the way pcretest operates.
243       REG_ICASE is set if /i is present, and REG_NEWLINE is set if  
244       /m    is    present.    The    wrapper    functions    force         The  /+ modifier requests that as well as outputting the substring that
245       PCRE_DOLLAR_ENDONLY    always,    and   PCRE_DOTALL   unless         matched the entire pattern, pcretest  should  in  addition  output  the
246       REG_NEWLINE is set.         remainder  of  the  subject  string. This is useful for tests where the
247           subject contains multiple copies of the same substring. If the +  modi-
248       The /8 modifier  causes  pcretest  to  call  PCRE  with  the         fier  appears  twice, the same action is taken for captured substrings.
249       PCRE_UTF8  option set. This turns on support for UTF-8 char-         In each case the remainder is output on the following line with a  plus
250       acter handling in PCRE, provided that it was  compiled  with         character  following  the  capture number. Note that this modifier must
251       this  support  enabled.  This  modifier also causes any non-         not immediately follow the /S modifier because /S+ has another meaning.
252       printing characters in output strings to  be  printed  using  
253       the \x{hh...} notation if they are valid UTF-8 sequences.         The /= modifier requests that the  values  of  all  potential  captured
254           parentheses  be  output  after a match by pcre_exec(). By default, only
255       If the /? modifier is used with /8, it  causes  pcretest  to         those up to the highest one actually used in the match are output (cor-
256       call  pcre_compile()  with the PCRE_NO_UTF8_CHECK option, to         responding  to the return code from pcre_exec()). Values in the offsets
257       suppress the checking of the string for UTF-8 validity.         vector corresponding to higher numbers should be set to -1,  and  these
258           are  output  as  "<unset>".  This modifier gives a way of checking that
259           this is happening.
260    
261           The /B modifier is a debugging feature. It requests that pcretest  out-
262           put  a representation of the compiled byte code after compilation. Nor-
263           mally this information contains length and offset values;  however,  if
264           /Z  is also present, this data is replaced by spaces. This is a special
265           feature for use in the automatic test scripts; it ensures that the same
266           output is generated for different internal link sizes.
267    
268           The  /D modifier is a PCRE debugging feature, and is equivalent to /BI,
269           that is, both the /B and the /I modifiers.
270    
271           The /F modifier causes pcretest to flip the byte order of the fields in
272           the  compiled  pattern  that  contain  2-byte  and 4-byte numbers. This
273           facility is for testing the feature in PCRE that allows it  to  execute
274           patterns that were compiled on a host with a different endianness. This
275           feature is not available when the POSIX  interface  to  PCRE  is  being
276           used,  that is, when the /P pattern modifier is specified. See also the
277           section about saving and reloading compiled patterns below.
278    
279           The /I modifier requests that pcretest  output  information  about  the
280           compiled  pattern (whether it is anchored, has a fixed first character,
281           and so on). It does this by calling pcre_fullinfo() after  compiling  a
282           pattern.  If  the pattern is studied, the results of that are also out-
283           put.
284    
285           The /K modifier requests pcretest to show names from backtracking  con-
286           trol  verbs  that  are  returned  from  calls to pcre_exec(). It causes
287           pcretest to create a pcre_extra block if one has not already been  cre-
288           ated by a call to pcre_study(), and to set the PCRE_EXTRA_MARK flag and
289           the mark field within it, every time that pcre_exec() is called. If the
290           variable  that  the  mark field points to is non-NULL for a match, non-
291           match, or partial match, pcretest prints the string to which it points.
292           For a match, this is shown on a line by itself, tagged with "MK:".  For
293           a non-match it is added to the message.
294    
295           The /L modifier must be followed directly by the name of a locale,  for
296           example,
297    
298             /pattern/Lfr_FR
299    
300           For this reason, it must be the last modifier. The given locale is set,
301           pcre_maketables() is called to build a set of character tables for  the
302           locale,  and  this  is then passed to pcre_compile() when compiling the
303           regular expression. Without an /L (or /T) modifier, NULL is  passed  as
304           the tables pointer; that is, /L applies only to the expression on which
305           it appears.
306    
307           The /M modifier causes the size of memory block used to hold  the  com-
308           piled  pattern to be output. This does not include the size of the pcre
309           block; it is just the actual compiled data. If the pattern is  success-
310           fully  studied  with the PCRE_STUDY_JIT_COMPILE option, the size of the
311           JIT compiled code is also output.
312    
313           If the /S modifier appears once, it causes pcre_study()  to  be  called
314           after  the  expression has been compiled, and the results used when the
315           expression is matched. If /S appears  twice,  it  suppresses  studying,
316           even if it was requested externally by the -s command line option. This
317           makes it possible to specify that certain patterns are always  studied,
318           and others are never studied, independently of -s. This feature is used
319           in the test files in a few cases where the output is different when the
320           pattern is studied.
321    
322           If  the  /S modifier is immediately followed by a + character, the call
323           to  pcre_study()  is  made  with  the  PCRE_STUDY_JIT_COMPILE   option,
324           requesting  just-in-time  optimization support if it is available. Note
325           that there is also a /+ modifier; it  must  not  be  given  immediately
326           after  /S  because this will be misinterpreted. If JIT studying is suc-
327           cessful, it will automatically be used when pcre_exec() is run,  except
328           when  incompatible  run-time  options  are specified. These include the
329           partial matching options; a complete list is given in the pcrejit docu-
330           mentation.  See  also the \J escape sequence below for a way of setting
331           the size of the JIT stack.
332    
333           The /T modifier must be followed by a single digit. It  causes  a  spe-
334           cific  set of built-in character tables to be passed to pcre_compile().
335           It is used in the standard PCRE tests to check behaviour with different
336           character tables. The digit specifies the tables as follows:
337    
338             0   the default ASCII tables, as distributed in
339                   pcre_chartables.c.dist
340             1   a set of tables defining ISO 8859 characters
341    
342           In  table 1, some characters whose codes are greater than 128 are iden-
343           tified as letters, digits, spaces, etc.
344    
345       Using the POSIX wrapper API
346    
347           The /P modifier causes pcretest to call PCRE via the POSIX wrapper  API
348           rather than its native API. When /P is set, the following modifiers set
349           options for the regcomp() function:
350    
351             /i    REG_ICASE
352             /m    REG_NEWLINE
353             /N    REG_NOSUB
354             /s    REG_DOTALL     )
355             /U    REG_UNGREEDY   ) These options are not part of
356             /W    REG_UCP        )   the POSIX standard
357             /8    REG_UTF8       )
358    
359           The /+ modifier works as  described  above.  All  other  modifiers  are
360           ignored.
361    
362    
363    DATA LINES
364    
365           Before  each  data  line is passed to pcre_exec(), leading and trailing
366           white space is removed, and it is then scanned for \ escapes.  Some  of
367           these  are  pretty esoteric features, intended for checking out some of
368           the more complicated features of PCRE. If you are just  testing  "ordi-
369           nary"  regular  expressions,  you probably don't need any of these. The
370           following escapes are recognized:
371    
372             \a         alarm (BEL, \x07)
373             \b         backspace (\x08)
374             \e         escape (\x27)
375             \f         form feed (\x0c)
376             \n         newline (\x0a)
377             \qdd       set the PCRE_MATCH_LIMIT limit to dd
378                          (any number of digits)
379             \r         carriage return (\x0d)
380             \t         tab (\x09)
381             \v         vertical tab (\x0b)
382             \nnn       octal character (up to 3 octal digits)
383                          always a byte unless > 255 in UTF-8 mode
384             \xhh       hexadecimal byte (up to 2 hex digits)
385             \x{hh...}  hexadecimal character, any number of digits
386                          in UTF-8 mode
387             \A         pass the PCRE_ANCHORED option to pcre_exec()
388                          or pcre_dfa_exec()
389             \B         pass the PCRE_NOTBOL option to pcre_exec()
390                          or pcre_dfa_exec()
391             \Cdd       call pcre_copy_substring() for substring dd
392                          after a successful match (number less than 32)
393             \Cname     call pcre_copy_named_substring() for substring
394                          "name" after a successful match (name termin-
395                          ated by next non alphanumeric character)
396             \C+        show the current captured substrings at callout
397                          time
398             \C-        do not supply a callout function
399             \C!n       return 1 instead of 0 when callout number n is
400                          reached
401             \C!n!m     return 1 instead of 0 when callout number n is
402                          reached for the nth time
403             \C*n       pass the number n (may be negative) as callout
404                          data; this is used as the callout return value
405             \D         use the pcre_dfa_exec() match function
406             \F         only shortest match for pcre_dfa_exec()
407             \Gdd       call pcre_get_substring() for substring dd
408                          after a successful match (number less than 32)
409             \Gname     call pcre_get_named_substring() for substring
410                          "name" after a successful match (name termin-
411                          ated by next non-alphanumeric character)
412             \Jdd       set up a JIT stack of dd kilobytes maximum (any
413                          number of digits)
414             \L         call pcre_get_substringlist() after a
415                          successful match
416             \M         discover the minimum MATCH_LIMIT and
417                          MATCH_LIMIT_RECURSION settings
418             \N         pass the PCRE_NOTEMPTY option to pcre_exec()
419                          or pcre_dfa_exec(); if used twice, pass the
420                          PCRE_NOTEMPTY_ATSTART option
421             \Odd       set the size of the output vector passed to
422                          pcre_exec() to dd (any number of digits)
423             \P         pass the PCRE_PARTIAL_SOFT option to pcre_exec()
424                          or pcre_dfa_exec(); if used twice, pass the
425                          PCRE_PARTIAL_HARD option
426             \Qdd       set the PCRE_MATCH_LIMIT_RECURSION limit to dd
427                          (any number of digits)
428             \R         pass the PCRE_DFA_RESTART option to pcre_dfa_exec()
429             \S         output details of memory get/free calls during matching
430             \Y         pass the PCRE_NO_START_OPTIMIZE option to pcre_exec()
431                          or pcre_dfa_exec()
432             \Z         pass the PCRE_NOTEOL option to pcre_exec()
433                          or pcre_dfa_exec()
434             \?         pass the PCRE_NO_UTF8_CHECK option to
435                          pcre_exec() or pcre_dfa_exec()
436             \>dd       start the match at offset dd (optional "-"; then
437                          any number of digits); this sets the startoffset
438                          argument for pcre_exec() or pcre_dfa_exec()
439             \<cr>      pass the PCRE_NEWLINE_CR option to pcre_exec()
440                          or pcre_dfa_exec()
441             \<lf>      pass the PCRE_NEWLINE_LF option to pcre_exec()
442                          or pcre_dfa_exec()
443             \<crlf>    pass the PCRE_NEWLINE_CRLF option to pcre_exec()
444                          or pcre_dfa_exec()
445             \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre_exec()
446                          or pcre_dfa_exec()
447             \<any>     pass the PCRE_NEWLINE_ANY option to pcre_exec()
448                          or pcre_dfa_exec()
449    
450           Note that \xhh always specifies one byte,  even  in  UTF-8  mode;  this
451           makes it possible to construct invalid UTF-8 sequences for testing pur-
452           poses. On the other hand, \x{hh} is interpreted as a UTF-8 character in
453           UTF-8  mode, generating more than one byte if the value is greater than
454           127. When not in UTF-8 mode, it generates one byte for values less than
455           256, and causes an error for greater values.
456    
457           The  escapes  that  specify  line ending sequences are literal strings,
458           exactly as shown. No more than one newline setting should be present in
459           any data line.
460    
461           A  backslash  followed by anything else just escapes the anything else.
462           If the very last character is a backslash, it is ignored. This gives  a
463           way  of  passing  an empty line as data, since a real empty line termi-
464           nates the data input.
465    
466           The \J escape provides a way of setting the maximum stack size that  is
467           used  by the just-in-time optimization code. It is ignored if JIT opti-
468           mization is not being used. Providing a stack that is larger  than  the
469           default 32K is necessary only for very complicated patterns.
470    
471           If  \M  is present, pcretest calls pcre_exec() several times, with dif-
472           ferent values in the match_limit and  match_limit_recursion  fields  of
473           the  pcre_extra  data structure, until it finds the minimum numbers for
474           each parameter  that  allow  pcre_exec()  to  complete  without  error.
475           Because  this  is testing a specific feature of the normal interpretive
476           pcre_exec() execution, the use of any JIT optimization that might  have
477           been set up by the /S+ qualifier of -s+ option is disabled.
478    
479           The  match_limit number is a measure of the amount of backtracking that
480           takes place, and checking it out can be instructive.  For  most  simple
481           matches,  the  number  is quite small, but for patterns with very large
482           numbers of matching possibilities, it can  become  large  very  quickly
483           with  increasing  length  of  subject string. The match_limit_recursion
484           number is a measure of how much stack (or, if  PCRE  is  compiled  with
485           NO_RECURSE,  how  much  heap)  memory  is  needed to complete the match
486           attempt.
487    
488           When \O is used, the value specified may be higher or  lower  than  the
489           size set by the -O command line option (or defaulted to 45); \O applies
490           only to the call of pcre_exec() for the line in which it appears.
491    
492           If the /P modifier was present on the pattern, causing the POSIX  wrap-
493           per  API  to  be  used, the only option-setting sequences that have any
494           effect are \B,  \N,  and  \Z,  causing  REG_NOTBOL,  REG_NOTEMPTY,  and
495           REG_NOTEOL, respectively, to be passed to regexec().
496    
497           The  use of \x{hh...} to represent UTF-8 characters is not dependent on
498           the use of the /8 modifier on the pattern.  It  is  recognized  always.
499           There  may  be  any number of hexadecimal digits inside the braces. The
500           result is from one to six bytes,  encoded  according  to  the  original
501           UTF-8  rules  of  RFC  2279.  This  allows for values in the range 0 to
502           0x7FFFFFFF. Note that not all of those are valid Unicode  code  points,
503           or  indeed  valid  UTF-8 characters according to the later rules in RFC
504           3629.
505    
506    
507    THE ALTERNATIVE MATCHING FUNCTION
508    
509           By  default,  pcretest  uses  the  standard  PCRE  matching   function,
510           pcre_exec() to match each data line. From release 6.0, PCRE supports an
511           alternative matching function, pcre_dfa_test(),  which  operates  in  a
512           different  way,  and has some restrictions. The differences between the
513           two functions are described in the pcrematching documentation.
514    
515           If a data line contains the \D escape sequence, or if the command  line
516           contains  the -dfa option, the alternative matching function is called.
517           This function finds all possible matches at a given point. If, however,
518           the  \F escape sequence is present in the data line, it stops after the
519           first match is found. This is always the shortest possible match.
520    
521    
522    DEFAULT OUTPUT FROM PCRETEST
523    
524           This section describes the output when the  normal  matching  function,
525           pcre_exec(), is being used.
526    
527           When a match succeeds, pcretest outputs the list of captured substrings
528           that pcre_exec() returns, starting with number 0 for  the  string  that
529           matched  the  whole  pattern. Otherwise, it outputs "No match" when the
530           return is PCRE_ERROR_NOMATCH, and "Partial match:" followed by the par-
531           tially  matching substring when pcre_exec() returns PCRE_ERROR_PARTIAL.
532           (Note that this is the entire substring that was inspected  during  the
533           partial  match; it may include characters before the actual match start
534           if a lookbehind assertion, \K, \b, or \B was involved.) For  any  other
535           return,  pcretest  outputs  the  PCRE negative error number and a short
536           descriptive phrase. If the error is a failed UTF-8  string  check,  the
537           byte  offset  of the start of the failing character and the reason code
538           are also output, provided that the size of  the  output  vector  is  at
539           least two. Here is an example of an interactive pcretest run.
540    
541             $ pcretest
542             PCRE version 8.13 2011-04-30
543    
544               re> /^abc(\d+)/
545             data> abc123
546              0: abc123
547              1: 123
548             data> xyz
549             No match
550    
551           Unset capturing substrings that are not followed by one that is set are
552           not returned by pcre_exec(), and are not shown by pcretest. In the fol-
553           lowing  example, there are two capturing substrings, but when the first
554           data line is matched, the second, unset  substring  is  not  shown.  An
555           "internal"  unset  substring  is  shown as "<unset>", as for the second
556           data line.
557    
558               re> /(a)|(b)/
559             data> a
560              0: a
561              1: a
562             data> b
563              0: b
564              1: <unset>
565              2: b
566    
567           If the strings contain any non-printing characters, they are output  as
568           \0x  escapes,  or  as \x{...} escapes if the /8 modifier was present on
569           the pattern. See below for the definition of  non-printing  characters.
570           If  the pattern has the /+ modifier, the output for substring 0 is fol-
571           lowed by the the rest of the subject string, identified  by  "0+"  like
572           this:
573    
574               re> /cat/+
575             data> cataract
576              0: cat
577              0+ aract
578    
579           If  the  pattern  has  the /g or /G modifier, the results of successive
580           matching attempts are output in sequence, like this:
581    
582               re> /\Bi(\w\w)/g
583             data> Mississippi
584              0: iss
585              1: ss
586              0: iss
587              1: ss
588              0: ipp
589              1: pp
590    
591           "No match" is output only if the first match attempt fails. Here is  an
592           example  of a failure message (the offset 4 that is specified by \>4 is
593           past the end of the subject string):
594    
595               re> /xyz/
596             data> xyz\>4
597             Error -24 (bad offset value)
598    
599           If any of the sequences \C, \G, or \L are present in a data  line  that
600           is  successfully  matched,  the substrings extracted by the convenience
601           functions are output with C, G, or L after the string number instead of
602           a colon. This is in addition to the normal full list. The string length
603           (that is, the return from the extraction function) is given  in  paren-
604           theses after each string for \C and \G.
605    
606           Note that whereas patterns can be continued over several lines (a plain
607           ">" prompt is used for continuations), data lines may not. However new-
608           lines  can  be included in data by means of the \n escape (or \r, \r\n,
609           etc., depending on the newline sequence setting).
610    
611    
612    OUTPUT FROM THE ALTERNATIVE MATCHING FUNCTION
613    
614           When the alternative matching function, pcre_dfa_exec(),  is  used  (by
615           means  of  the \D escape sequence or the -dfa command line option), the
616           output consists of a list of all the matches that start  at  the  first
617           point in the subject where there is at least one match. For example:
618    
619               re> /(tang|tangerine|tan)/
620             data> yellow tangerine\D
621              0: tangerine
622              1: tang
623              2: tan
624    
625           (Using  the  normal  matching function on this data finds only "tang".)
626           The longest matching string is always given first (and numbered  zero).
627           After a PCRE_ERROR_PARTIAL return, the output is "Partial match:", fol-
628           lowed by the partially matching  substring.  (Note  that  this  is  the
629           entire  substring  that  was inspected during the partial match; it may
630           include characters before the actual match start if a lookbehind asser-
631           tion, \K, \b, or \B was involved.)
632    
633           If /g is present on the pattern, the search for further matches resumes
634           at the end of the longest match. For example:
635    
636               re> /(tang|tangerine|tan)/g
637             data> yellow tangerine and tangy sultana\D
638              0: tangerine
639              1: tang
640              2: tan
641              0: tang
642              1: tan
643              0: tan
644    
645           Since the matching function does not  support  substring  capture,  the
646           escape  sequences  that  are concerned with captured substrings are not
647           relevant.
648    
649    
650    RESTARTING AFTER A PARTIAL MATCH
651    
652           When the alternative matching function has given the PCRE_ERROR_PARTIAL
653           return,  indicating that the subject partially matched the pattern, you
654           can restart the match with additional subject data by means of  the  \R
655           escape sequence. For example:
656    
657               re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/
658             data> 23ja\P\D
659             Partial match: 23ja
660             data> n05\R\D
661              0: n05
662    
663           For  further  information  about  partial matching, see the pcrepartial
664           documentation.
665    
666    
667  CALLOUTS  CALLOUTS
668    
669       If the pattern contains  any  callout  requests,  pcretest's         If the pattern contains any callout requests, pcretest's callout  func-
670       callout function will be called. By default, it displays the         tion  is  called  during  matching. This works with both matching func-
671       callout number, and the start and current positions  in  the         tions. By default, the called function displays the callout number, the
672       text at the callout time. For example, the output         start  and  current  positions in the text at the callout time, and the
673           next pattern item to be tested. For example, the output
674         --->pqrabcdef  
675           0    ^  ^           --->pqrabcdef
676               0    ^  ^     \d
677       indicates that callout number 0 occurred for a match attempt  
678       starting at the fourth character of the subject string, when         indicates that callout number 0 occurred for a match  attempt  starting
679       the pointer was at the seventh character. The callout  func-         at  the fourth character of the subject string, when the pointer was at
680       tion returns zero (carry on matching) by default.         the seventh character of the data, and when the next pattern  item  was
681           \d.  Just  one  circumflex is output if the start and current positions
682       Inserting callouts may be helpful  when  using  pcretest  to         are the same.
683       check  complicated regular expressions. For further informa-  
684       tion about callouts, see the pcrecallout documentation.         Callouts numbered 255 are assumed to be automatic callouts, inserted as
685           a  result  of the /C pattern modifier. In this case, instead of showing
686       For testing the PCRE library, additional control of  callout         the callout number, the offset in the pattern, preceded by a  plus,  is
687       behaviour  is available via escape sequences in the data, as         output. For example:
688       described in the following section.  In  particular,  it  is  
689       possible to pass in a number as callout data (the default is             re> /\d?[A-E]\*/C
690       zero). If the callout function receives a  non-zero  number,           data> E*
691       it returns that value instead of zero.           --->E*
692              +0 ^      \d?
693              +3 ^      [A-E]
694              +8 ^^     \*
695             +10 ^ ^
696              0: E*
697    
698           If a pattern contains (*MARK) items, an additional line is output when-
699           ever a change of latest mark is passed to  the  callout  function.  For
700           example:
701    
702               re> /a(*MARK:X)bc/C
703             data> abc
704             --->abc
705              +0 ^       a
706              +1 ^^      (*MARK:X)
707             +10 ^^      b
708             Latest Mark: X
709             +11 ^ ^     c
710             +12 ^  ^
711              0: abc
712    
713           The  mark  changes between matching "a" and "b", but stays the same for
714           the rest of the match, so nothing more is output. If, as  a  result  of
715           backtracking,  the  mark  reverts to being unset, the text "<unset>" is
716           output.
717    
718           The callout function in pcretest returns zero (carry  on  matching)  by
719           default,  but you can use a \C item in a data line (as described above)
720           to change this and other parameters of the callout.
721    
722           Inserting callouts can be helpful when using pcretest to check  compli-
723           cated  regular expressions. For further information about callouts, see
724           the pcrecallout documentation.
725    
726    
727    NON-PRINTING CHARACTERS
728    
729           When pcretest is outputting text in the compiled version of a  pattern,
730           bytes  other  than 32-126 are always treated as non-printing characters
731           are are therefore shown as hex escapes.
732    
733           When pcretest is outputting text that is a matched part  of  a  subject
734           string,  it behaves in the same way, unless a different locale has been
735           set for the  pattern  (using  the  /L  modifier).  In  this  case,  the
736           isprint() function to distinguish printing and non-printing characters.
737    
738    
739    SAVING AND RELOADING COMPILED PATTERNS
740    
741           The  facilities  described  in  this section are not available when the
742           POSIX interface to PCRE is being used, that is,  when  the  /P  pattern
743           modifier is specified.
744    
745           When the POSIX interface is not in use, you can cause pcretest to write
746           a compiled pattern to a file, by following the modifiers with >  and  a
747           file name.  For example:
748    
749             /pattern/im >/some/file
750    
751           See  the pcreprecompile documentation for a discussion about saving and
752           re-using compiled patterns.  Note that if the pattern was  successfully
753           studied with JIT optimization, the JIT data cannot be saved.
754    
755           The  data  that  is  written  is  binary. The first eight bytes are the
756           length of the compiled pattern data  followed  by  the  length  of  the
757           optional  study  data,  each  written as four bytes in big-endian order
758           (most significant byte first). If there is no study  data  (either  the
759           pattern was not studied, or studying did not return any data), the sec-
760           ond length is zero. The lengths are followed by an exact  copy  of  the
761           compiled  pattern.  If  there is additional study data, this (excluding
762           any JIT data) follows immediately after  the  compiled  pattern.  After
763           writing the file, pcretest expects to read a new pattern.
764    
765           A  saved  pattern  can  be reloaded into pcretest by specifying < and a
766           file name instead of a pattern. The name of the file must not contain a
767           < character, as otherwise pcretest will interpret the line as a pattern
768           delimited by < characters.  For example:
769    
770              re> </some/file
771             Compiled pattern loaded from /some/file
772             No study data
773    
774           If the pattern was previously studied with the  JIT  optimization,  the
775           JIT  information cannot be saved and restored, and so is lost. When the
776           pattern has been loaded, pcretest proceeds to read data  lines  in  the
777           usual way.
778    
779           You  can copy a file written by pcretest to a different host and reload
780           it there, even if the new host has opposite endianness to  the  one  on
781           which  the pattern was compiled. For example, you can compile on an i86
782           machine and run on a SPARC machine.
783    
784           File names for saving and reloading can be absolute  or  relative,  but
785           note  that the shell facility of expanding a file name that starts with
786           a tilde (~) is not available.
787    
788           The ability to save and reload files in pcretest is intended for  test-
789           ing  and experimentation. It is not intended for production use because
790           only a single pattern can be written to a file. Furthermore,  there  is
791           no  facility  for  supplying  custom  character  tables  for use with a
792           reloaded pattern. If the original  pattern  was  compiled  with  custom
793           tables,  an  attempt to match a subject string using a reloaded pattern
794           is likely to cause pcretest to crash.  Finally, if you attempt to  load
795           a file that is not in the correct format, the result is undefined.
796    
797    
798  DATA LINES  SEE ALSO
799    
800       Before each data line is passed to pcre_exec(), leading  and         pcre(3), pcreapi(3), pcrecallout(3), pcrejit, pcrematching(3), pcrepar-
801       trailing whitespace is removed, and it is then scanned for \         tial(d), pcrepattern(3), pcreprecompile(3).
      escapes.  Some  of  these  are  pretty  esoteric   features,  
      intended  for  checking  out  some  of  the more complicated  
      features of PCRE. If you are just testing "ordinary" regular  
      expressions,  you probably don't need any of these. The fol-  
      lowing escapes are recognized:  
   
        \a         alarm (= BEL)  
        \b         backspace  
        \e         escape  
        \f         formfeed  
        \n         newline  
        \r         carriage return  
        \t         tab  
        \v         vertical tab  
        \nnn       octal character (up to 3 octal digits)  
        \xhh       hexadecimal character (up to 2 hex digits)  
        \x{hh...}  hexadecimal character, any number of digits  
                     in UTF-8 mode  
        \A         pass the PCRE_ANCHORED option to pcre_exec()  
        \B         pass the PCRE_NOTBOL option to pcre_exec()  
        \Cdd       call pcre_copy_substring() for substring dd  
                     after a successful match (any decimal number  
                     less than 32)  
        \Cname     call pcre_copy_named_substring() for substring  
   
                     "name" after a successful match (name termin-  
                     ated by next non alphanumeric character)  
        \C+        show the current captured substrings at callout  
                     time  
        \C-        do not supply a callout function  
        \C!n       return 1 instead of 0 when callout number n is  
                     reached  
        \C!n!m     return 1 instead of 0 when callout number n is  
                     reached for the nth time  
        \C*n       pass the number n (may be negative) as callout  
                     data  
        \Gdd       call pcre_get_substring() for substring dd  
                     after a successful match (any decimal number  
                     less than 32)  
        \Gname     call pcre_get_named_substring() for substring  
                     "name" after a successful match (name termin-  
                     ated by next non-alphanumeric character)  
        \L         call pcre_get_substringlist() after a  
                     successful match  
        \M         discover the minimum MATCH_LIMIT setting  
        \N         pass the PCRE_NOTEMPTY option to pcre_exec()  
        \Odd       set the size of the output vector passed to  
                     pcre_exec() to dd (any number of decimal  
                     digits)  
        \Z         pass the PCRE_NOTEOL option to pcre_exec()  
        \?         pass the PCRE_NO_UTF8_CHECK option to  
                     pcre_exec()  
   
      If \M is present, pcretest calls pcre_exec() several  times,  
      with  different  values  in  the  match_limit  field  of the  
      pcre_extra data structure, until it finds the minimum number  
      that is needed for pcre_exec() to complete. This number is a  
      measure of the amount of  recursion  and  backtracking  that  
      takes  place,  and  checking  it out can be instructive. For  
      most simple matches, the number is quite small, but for pat-  
      terns  with very large numbers of matching possibilities, it  
      can become large very quickly with increasing length of sub-  
      ject string.  
   
      When \O is used, it may be higher or lower than the size set  
      by  the  -O  option (or defaulted to 45); \O applies only to  
      the call of pcre_exec() for the line in which it appears.  
   
      A backslash followed by anything else just escapes the  any-  
      thing else. If the very last character is a backslash, it is  
      ignored. This gives a way of passing an empty line as  data,  
      since a real empty line terminates the data input.  
   
      If /P was present on the regex, causing  the  POSIX  wrapper  
      API  to  be  used,  only  B,  and Z have any effect, causing  
      REG_NOTBOL and REG_NOTEOL to be passed to regexec()  respec-  
      tively.  
      The use of \x{hh...} to represent UTF-8  characters  is  not  
      dependent  on  the use of the /8 modifier on the pattern. It  
      is recognized always. There may be any number of hexadecimal  
      digits  inside  the  braces.  The  result is from one to six  
      bytes, encoded according to the UTF-8 rules.  
   
   
 OUTPUT FROM PCRETEST  
   
      When a match succeeds, pcretest outputs the list of captured  
      substrings  that pcre_exec() returns, starting with number 0  
      for the string that matched the whole pattern.  Here  is  an  
      example of an interactive pcretest run.  
   
        $ pcretest  
        PCRE version 4.00 08-Jan-2003  
   
          re> /^abc(\d+)/  
        data> abc123  
         0: abc123  
         1: 123  
        data> xyz  
        No match  
   
      If the strings contain any non-printing characters, they are  
      output  as  \0x  escapes,  or  as  \x{...} escapes if the /8  
      modifier was present on the pattern. If the pattern has  the  
      /+  modifier, then the output for substring 0 is followed by  
      the the rest of the subject string, identified by "0+"  like  
      this:  
   
          re> /cat/+  
        data> cataract  
         0: cat  
         0+ aract  
   
      If the pattern has the /g or /G  modifier,  the  results  of  
      successive  matching  attempts  are output in sequence, like  
      this:  
   
          re> /\Bi(\w\w)/g  
        data> Mississippi  
         0: iss  
         1: ss  
         0: iss  
         1: ss  
         0: ipp  
         1: pp  
   
      "No match" is output only if the first match attempt fails.  
   
      If any of the sequences \C, \G, or \L are present in a  data  
      line  that is successfully matched, the substrings extracted  
      by the convenience functions are output  with  C,  G,  or  L  
      after the string number instead of a colon. This is in addi-  
      tion to the normal full list. The string  length  (that  is,  
      the  return  from  the  extraction  function)  is  given  in  
      parentheses after each string for \C and \G.  
   
      Note that while patterns can be continued over several lines  
      (a  plain  ">" prompt is used for continuations), data lines  
      may not. However newlines can be included in data  by  means  
      of the \n escape.  
802    
803    
804  AUTHOR  AUTHOR
805    
806       Philip Hazel <ph10@cam.ac.uk>         Philip Hazel
807       University Computing Service,         University Computing Service
808       Cambridge CB2 3QG, England.         Cambridge CB2 3QH, England.
809    
810    
811    REVISION
812    
813  Last updated: 20 August 2003         Last updated: 02 December 2011
814  Copyright (c) 1997-2003 University of Cambridge.         Copyright (c) 1997-2011 University of Cambridge.

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