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revision 683 by ph10, Tue Sep 6 10:37:15 2011 UTC revision 691 by ph10, Sun Sep 11 14:31:21 2011 UTC
# Line 41  PCRE - Perl-compatible regular expressio Line 41  PCRE - Perl-compatible regular expressio
41  .PP  .PP
42  .B void pcre_jit_stack_free(pcre_jit_stack *\fIstack\fP);  .B void pcre_jit_stack_free(pcre_jit_stack *\fIstack\fP);
43  .PP  .PP
44  .B void pcre_assign_jit_stack(pcre_extra *\fIextra\fP,  .B void pcre_assign_jit_stack(pcre_extra *\fIextra\fP,
45  .ti +5n  .ti +5n
46  .B pcre_jit_callback \fIcallback\fP, void *\fIdata\fP);  .B pcre_jit_callback \fIcallback\fP, void *\fIdata\fP);
47  .PP  .PP
# Line 111  PCRE - Perl-compatible regular expressio Line 111  PCRE - Perl-compatible regular expressio
111  .B int pcre_config(int \fIwhat\fP, void *\fIwhere\fP);  .B int pcre_config(int \fIwhat\fP, void *\fIwhere\fP);
112  .PP  .PP
113  .B char *pcre_version(void);  .B char *pcre_version(void);
114  .PP  .
115    .
116    .SH "PCRE NATIVE API INDIRECTED FUNCTIONS"
117    .rs
118    .sp
119  .B void *(*pcre_malloc)(size_t);  .B void *(*pcre_malloc)(size_t);
120  .PP  .PP
121  .B void (*pcre_free)(void *);  .B void (*pcre_free)(void *);
# Line 168  documentation, and the Line 172  documentation, and the
172  documentation describes how to compile and run it.  documentation describes how to compile and run it.
173  .P  .P
174  Just-in-time compiler support is an optional feature of PCRE that can be built  Just-in-time compiler support is an optional feature of PCRE that can be built
175  in appropriate hardware environments. It greatly speeds up the matching  in appropriate hardware environments. It greatly speeds up the matching
176  performance of many patterns. Simple programs can request its use if available.  performance of many patterns. Simple programs can easily request that it be
177  More complicated programs might need to make use of the  used if available, by setting an option that is ignored when it is not
178  \fBpcre_jit_stack_alloc()\fP, \fBpcre_jit_stack_free()\fP, and  relevant. More complicated programs might need to make use of the functions
179  \fBpcre_assign_jit_stack()\fP functions in order to control its memory usage.  \fBpcre_jit_stack_alloc()\fP, \fBpcre_jit_stack_free()\fP, and
180    \fBpcre_assign_jit_stack()\fP in order to control the JIT code's memory usage.
181  These functions are discussed in the  These functions are discussed in the
182  .\" HREF  .\" HREF
183  \fBpcrejit\fP  \fBpcrejit\fP
# Line 310  callout function pointed to by \fBpcre_c Line 315  callout function pointed to by \fBpcre_c
315  The compiled form of a regular expression is not altered during matching, so  The compiled form of a regular expression is not altered during matching, so
316  the same compiled pattern can safely be used by several threads at once.  the same compiled pattern can safely be used by several threads at once.
317  .P  .P
318  If the just-in-time optimization feature is being used, it needs separate  If the just-in-time optimization feature is being used, it needs separate
319  memory stack areas for each thread. See the  memory stack areas for each thread. See the
320  .\" HREF  .\" HREF
321  \fBpcrejit\fP  \fBpcrejit\fP
# Line 360  properties is available; otherwise it is Line 365  properties is available; otherwise it is
365  .sp  .sp
366    PCRE_CONFIG_JIT    PCRE_CONFIG_JIT
367  .sp  .sp
368  The output is an integer that is set to one if support for just-in-time  The output is an integer that is set to one if support for just-in-time
369  compiling is available; otherwise it is set to zero.  compiling is available; otherwise it is set to zero.
370  .sp  .sp
371    PCRE_CONFIG_NEWLINE    PCRE_CONFIG_NEWLINE
372  .sp  .sp
# Line 883  If studying the pattern does not produce Line 888  If studying the pattern does not produce
888  wants to pass any of the other fields to \fBpcre_exec()\fP or  wants to pass any of the other fields to \fBpcre_exec()\fP or
889  \fBpcre_dfa_exec()\fP, it must set up its own \fBpcre_extra\fP block.  \fBpcre_dfa_exec()\fP, it must set up its own \fBpcre_extra\fP block.
890  .P  .P
891  The second argument of \fBpcre_study()\fP contains option bits. There is only  The second argument of \fBpcre_study()\fP contains option bits. There is only
892  one option: PCRE_STUDY_JIT_COMPILE. If this is set, and the just-in-time  one option: PCRE_STUDY_JIT_COMPILE. If this is set, and the just-in-time
893  compiler is available, the pattern is further compiled into machine code that  compiler is available, the pattern is further compiled into machine code that
894  executes much faster than the \fBpcre_exec()\fP matching function. If  executes much faster than the \fBpcre_exec()\fP matching function. If
895  the just-in-time compiler is not available, this option is ignored. All other  the just-in-time compiler is not available, this option is ignored. All other
896  bits in the \fIoptions\fP argument must be zero.  bits in the \fIoptions\fP argument must be zero.
897  .P  .P
898  JIT compilation is a heavyweight optimization. It can take some time for  JIT compilation is a heavyweight optimization. It can take some time for
899  patterns to be analyzed, and for one-off matches and simple patterns the  patterns to be analyzed, and for one-off matches and simple patterns the
900  benefit of faster execution might be offset by a much slower study time.  benefit of faster execution might be offset by a much slower study time.
901  Not all patterns can be optimized by the JIT compiler. For those that cannot be  Not all patterns can be optimized by the JIT compiler. For those that cannot be
902  handled, matching automatically falls back to the \fBpcre_exec()\fP  handled, matching automatically falls back to the \fBpcre_exec()\fP
903  interpreter. For more details, see the  interpreter. For more details, see the
904  .\" HREF  .\" HREF
# Line 915  API for release 8.20. For earlier versio Line 920  API for release 8.20. For earlier versio
920  where PCRE_STUDY_JIT_COMPILE is not used, but it is advisable to change to the  where PCRE_STUDY_JIT_COMPILE is not used, but it is advisable to change to the
921  new function when convenient.  new function when convenient.
922  .P  .P
923  This is a typical way in which \fBpcre_study\fP() is used (except that in a  This is a typical way in which \fBpcre_study\fP() is used (except that in a
924  real application there should be tests for errors):  real application there should be tests for errors):
925  .sp  .sp
926    int rc;    int rc;
# Line 927  real application there should be tests f Line 932  real application there should be tests f
932      0,              /* no options */      0,              /* no options */
933      &error);        /* set to NULL or points to a message */      &error);        /* set to NULL or points to a message */
934    rc = pcre_exec(   /* see below for details of pcre_exec() options */    rc = pcre_exec(   /* see below for details of pcre_exec() options */
935      re, sd, "subject", 7, 0, 0, ovector, 30);      re, sd, "subject", 7, 0, 0, ovector, 30);
936    ...    ...
937    pcre_free_study(sd);    pcre_free_study(sd);
938    pcre_free(re);    pcre_free(re);
939  .sp  .sp
940  Studying a pattern does two things: first, a lower bound for the length of  Studying a pattern does two things: first, a lower bound for the length of
941  subject string that is needed to match the pattern is computed. This does not  subject string that is needed to match the pattern is computed. This does not
# Line 945  single fixed starting character. A bitma Line 950  single fixed starting character. A bitma
950  created. This speeds up finding a position in the subject at which to start  created. This speeds up finding a position in the subject at which to start
951  matching.  matching.
952  .P  .P
953  These two optimizations apply to both \fBpcre_exec()\fP and  These two optimizations apply to both \fBpcre_exec()\fP and
954  \fBpcre_dfa_exec()\fP. However, they are not used by \fBpcre_exec()\fP if  \fBpcre_dfa_exec()\fP. However, they are not used by \fBpcre_exec()\fP if
955  \fBpcre_study()\fP is called with the PCRE_STUDY_JIT_COMPILE option, and  \fBpcre_study()\fP is called with the PCRE_STUDY_JIT_COMPILE option, and
956  just-in-time compiling is successful. The optimizations can be disabled by  just-in-time compiling is successful. The optimizations can be disabled by
957  setting the PCRE_NO_START_OPTIMIZE option when calling \fBpcre_exec()\fP or  setting the PCRE_NO_START_OPTIMIZE option when calling \fBpcre_exec()\fP or
# Line 1117  Return 1 if the (?J) or (?-J) option set Line 1122  Return 1 if the (?J) or (?-J) option set
1122  .sp  .sp
1123    PCRE_INFO_JIT    PCRE_INFO_JIT
1124  .sp  .sp
1125  Return 1 if the pattern was studied with the PCRE_STUDY_JIT_COMPILE option, and  Return 1 if the pattern was studied with the PCRE_STUDY_JIT_COMPILE option, and
1126  just-in-time compiling was successful. The fourth argument should point to an  just-in-time compiling was successful. The fourth argument should point to an
1127  \fBint\fP variable. A return value of 0 means that JIT support is not available  \fBint\fP variable. A return value of 0 means that JIT support is not available
1128  in this version of PCRE, or that the pattern was not studied with the  in this version of PCRE, or that the pattern was not studied with the
1129  PCRE_STUDY_JIT_COMPILE option, or that the JIT compiler could not handle this  PCRE_STUDY_JIT_COMPILE option, or that the JIT compiler could not handle this
1130  particular pattern. See the  particular pattern. See the
1131  .\" HREF  .\" HREF
1132  \fBpcrejit\fP  \fBpcrejit\fP
# Line 1372  fields (not necessarily in this order): Line 1377  fields (not necessarily in this order):
1377  .sp  .sp
1378    unsigned long int \fIflags\fP;    unsigned long int \fIflags\fP;
1379    void *\fIstudy_data\fP;    void *\fIstudy_data\fP;
1380    void *\fIexecutable_jit\fP;    void *\fIexecutable_jit\fP;
1381    unsigned long int \fImatch_limit\fP;    unsigned long int \fImatch_limit\fP;
1382    unsigned long int \fImatch_limit_recursion\fP;    unsigned long int \fImatch_limit_recursion\fP;
1383    void *\fIcallout_data\fP;    void *\fIcallout_data\fP;
# Line 1383  The \fIflags\fP field is a bitmap that s Line 1388  The \fIflags\fP field is a bitmap that s
1388  are set. The flag bits are:  are set. The flag bits are:
1389  .sp  .sp
1390    PCRE_EXTRA_STUDY_DATA    PCRE_EXTRA_STUDY_DATA
1391    PCRE_EXTRA_EXECUTABLE_JIT    PCRE_EXTRA_EXECUTABLE_JIT
1392    PCRE_EXTRA_MATCH_LIMIT    PCRE_EXTRA_MATCH_LIMIT
1393    PCRE_EXTRA_MATCH_LIMIT_RECURSION    PCRE_EXTRA_MATCH_LIMIT_RECURSION
1394    PCRE_EXTRA_CALLOUT_DATA    PCRE_EXTRA_CALLOUT_DATA
# Line 1406  calls repeatedly (sometimes recursively) Line 1411  calls repeatedly (sometimes recursively)
1411  imposed on the number of times this function is called during a match, which  imposed on the number of times this function is called during a match, which
1412  has the effect of limiting the amount of backtracking that can take place. For  has the effect of limiting the amount of backtracking that can take place. For
1413  patterns that are not anchored, the count restarts from zero for each position  patterns that are not anchored, the count restarts from zero for each position
1414  in the subject string.  in the subject string.
1415  .P  .P
1416  When \fBpcre_exec()\fP is called with a pattern that was successfully studied  When \fBpcre_exec()\fP is called with a pattern that was successfully studied
1417  with the PCRE_STUDY_JIT_COMPILE option, the way that the matching is executed  with the PCRE_STUDY_JIT_COMPILE option, the way that the matching is executed
1418  is entirely different. However, there is still the possibility of runaway  is entirely different. However, there is still the possibility of runaway
1419  matching that goes on for a very long time, and so the \fImatch_limit\fP value  matching that goes on for a very long time, and so the \fImatch_limit\fP value
1420  is also used in this case (but in a different way) to limit how long the  is also used in this case (but in a different way) to limit how long the
1421  matching can continue.  matching can continue.
# Line 1426  The \fImatch_limit_recursion\fP field is Line 1431  The \fImatch_limit_recursion\fP field is
1431  instead of limiting the total number of times that \fBmatch()\fP is called, it  instead of limiting the total number of times that \fBmatch()\fP is called, it
1432  limits the depth of recursion. The recursion depth is a smaller number than the  limits the depth of recursion. The recursion depth is a smaller number than the
1433  total number of calls, because not all calls to \fBmatch()\fP are recursive.  total number of calls, because not all calls to \fBmatch()\fP are recursive.
1434  This limit is of use only if it is set smaller than \fImatch_limit\fP.  This limit is of use only if it is set smaller than \fImatch_limit\fP.
1435  .P  .P
1436  Limiting the recursion depth limits the amount of machine stack that can be  Limiting the recursion depth limits the amount of machine stack that can be
1437  used, or, when PCRE has been compiled to use memory on the heap instead of the  used, or, when PCRE has been compiled to use memory on the heap instead of the
1438  stack, the amount of heap memory that can be used. This limit is relevant, and  stack, the amount of heap memory that can be used. This limit is not relevant,
1439  is ignored, when the pattern was successfully studied with  and is ignored, if the pattern was successfully studied with
1440  PCRE_STUDY_JIT_COMPILE.  PCRE_STUDY_JIT_COMPILE.
1441  .P  .P
1442  The default value for \fImatch_limit_recursion\fP can be set when PCRE is  The default value for \fImatch_limit_recursion\fP can be set when PCRE is
# Line 1491  zero. The only bits that may be set are Line 1496  zero. The only bits that may be set are
1496  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,
1497  PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_SOFT, and  PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_SOFT, and
1498  PCRE_PARTIAL_HARD.  PCRE_PARTIAL_HARD.
1499    .P
1500    If the pattern was successfully studied with the PCRE_STUDY_JIT_COMPILE option,
1501    the only supported options for JIT execution are PCRE_NO_UTF8_CHECK,
1502    PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NOTEMPTY_ATSTART. Note in
1503    particular that partial matching is not supported. If an unsupported option is
1504    used, JIT execution is disabled and the normal interpretive code in
1505    \fBpcre_exec()\fP is run.
1506  .sp  .sp
1507    PCRE_ANCHORED    PCRE_ANCHORED
1508  .sp  .sp
# Line 1797  string that it matched that is returned. Line 1809  string that it matched that is returned.
1809  .P  .P
1810  If the vector is too small to hold all the captured substring offsets, it is  If the vector is too small to hold all the captured substring offsets, it is
1811  used as far as possible (up to two-thirds of its length), and the function  used as far as possible (up to two-thirds of its length), and the function
1812  returns a value of zero. If the substring offsets are not of interest,  returns a value of zero. If neither the actual string matched not any captured
1813  \fBpcre_exec()\fP may be called with \fIovector\fP passed as NULL and  substrings are of interest, \fBpcre_exec()\fP may be called with \fIovector\fP
1814  \fIovecsize\fP as zero. However, if the pattern contains back references and  passed as NULL and \fIovecsize\fP as zero. However, if the pattern contains
1815  the \fIovector\fP is not big enough to remember the related substrings, PCRE  back references and the \fIovector\fP is not big enough to remember the related
1816  has to get additional memory for use during matching. Thus it is usually  substrings, PCRE has to get additional memory for use during matching. Thus it
1817  advisable to supply an \fIovector\fP.  is usually advisable to supply an \fIovector\fP of reasonable size.
1818    .P
1819    There are some cases where zero is returned (indicating vector overflow) when
1820    in fact the vector is exactly the right size for the final match. For example,
1821    consider the pattern
1822    .sp
1823      (a)(?:(b)c|bd)
1824    .sp
1825    If a vector of 6 elements (allowing for only 1 captured substring) is given
1826    with subject string "abd", \fBpcre_exec()\fP will try to set the second
1827    captured string, thereby recording a vector overflow, before failing to match
1828    "c" and backing up to try the second alternative. The zero return, however,
1829    does correctly indicate that the maximum number of slots (namely 2) have been
1830    filled. In similar cases where there is temporary overflow, but the final
1831    number of used slots is actually less than the maximum, a non-zero value is
1832    returned.
1833  .P  .P
1834  The \fBpcre_fullinfo()\fP function can be used to find out how many capturing  The \fBpcre_fullinfo()\fP function can be used to find out how many capturing
1835  subpatterns there are in a compiled pattern. The smallest size for  subpatterns there are in a compiled pattern. The smallest size for
# Line 1823  return from the function is 2, because t Line 1850  return from the function is 2, because t
1850  number is 1, and the offsets for for the second and third capturing subpatterns  number is 1, and the offsets for for the second and third capturing subpatterns
1851  (assuming the vector is large enough, of course) are set to -1.  (assuming the vector is large enough, of course) are set to -1.
1852  .P  .P
1853  \fBNote\fP: Elements in the first two-thids of \fIovector\fP that do not  \fBNote\fP: Elements in the first two-thirds of \fIovector\fP that do not
1854  correspond to capturing parentheses in the pattern are never changed. That is,  correspond to capturing parentheses in the pattern are never changed. That is,
1855  if a pattern contains \fIn\fP capturing parentheses, no more than  if a pattern contains \fIn\fP capturing parentheses, no more than
1856  \fIovector[0]\fP to \fIovector[2n+1]\fP are set by \fBpcre_exec()\fP. The other  \fIovector[0]\fP to \fIovector[2n+1]\fP are set by \fBpcre_exec()\fP. The other
# Line 1982  time. Line 2009  time.
2009  .sp  .sp
2010    PCRE_ERROR_JIT_STACKLIMIT (-27)    PCRE_ERROR_JIT_STACKLIMIT (-27)
2011  .sp  .sp
2012  This error is returned when a pattern that was successfully studied using the  This error is returned when a pattern that was successfully studied using the
2013  PCRE_STUDY_JIT_COMPILE option is matched, but the memory available for the  PCRE_STUDY_JIT_COMPILE option is being matched, but the memory available for
2014  just-in-time processing stack is not large enough. See the  the just-in-time processing stack is not large enough. See the
2015  .\" HREF  .\" HREF
2016  \fBpcrejit\fP  \fBpcrejit\fP
2017  .\"  .\"
2018  documentation for more details.  documentation for more details.
2019  .P  .P
2020  Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.  Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.
2021  .  .
# Line 2229  names are not included in the compiled c Line 2256  names are not included in the compiled c
2256  numbers. For this reason, the use of different names for subpatterns of the  numbers. For this reason, the use of different names for subpatterns of the
2257  same number causes an error at compile time.  same number causes an error at compile time.
2258  .  .
2259    .
2260  .SH "DUPLICATE SUBPATTERN NAMES"  .SH "DUPLICATE SUBPATTERN NAMES"
2261  .rs  .rs
2262  .sp  .sp
# Line 2428  returns data, even though the meaning of Line 2456  returns data, even though the meaning of
2456  The strings are returned in reverse order of length; that is, the longest  The strings are returned in reverse order of length; that is, the longest
2457  matching string is given first. If there were too many matches to fit into  matching string is given first. If there were too many matches to fit into
2458  \fIovector\fP, the yield of the function is zero, and the vector is filled with  \fIovector\fP, the yield of the function is zero, and the vector is filled with
2459  the longest matches. Unlike \fBpcre_exec()\fP, \fBpcre_dfa_exec()\fP can use  the longest matches. Unlike \fBpcre_exec()\fP, \fBpcre_dfa_exec()\fP can use
2460  the entire \fIovector\fP for returning matched strings.  the entire \fIovector\fP for returning matched strings.
2461  .  .
2462  .  .
# Line 2498  Cambridge CB2 3QH, England. Line 2526  Cambridge CB2 3QH, England.
2526  .rs  .rs
2527  .sp  .sp
2528  .nf  .nf
2529  Last updated: 29 August 2011  Last updated: 06 September 2011
2530  Copyright (c) 1997-2011 University of Cambridge.  Copyright (c) 1997-2011 University of Cambridge.
2531  .fi  .fi

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