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revision 678 by ph10, Sun Aug 28 15:23:03 2011 UTC revision 745 by ph10, Mon Nov 14 11:41:03 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 638  character). Thus, the pattern AB]CD beco Line 643  character). Thus, the pattern AB]CD beco
643  string (by default this causes the current matching alternative to fail). A  string (by default this causes the current matching alternative to fail). A
644  pattern such as (\e1)(a) succeeds when this option is set (assuming it can find  pattern such as (\e1)(a) succeeds when this option is set (assuming it can find
645  an "a" in the subject), whereas it fails by default, for Perl compatibility.  an "a" in the subject), whereas it fails by default, for Perl compatibility.
646    .P
647    (3) \eU matches an upper case "U" character; by default \eU causes a compile
648    time error (Perl uses \eU to upper case subsequent characters).
649    .P
650    (4) \eu matches a lower case "u" character unless it is followed by four
651    hexadecimal digits, in which case the hexadecimal number defines the code point
652    to match. By default, \eu causes a compile time error (Perl uses it to upper
653    case the following character).
654    .P
655    (5) \ex matches a lower case "x" character unless it is followed by two
656    hexadecimal digits, in which case the hexadecimal number defines the code point
657    to match. By default, as in Perl, a hexadecimal number is always expected after
658    \ex, but it may have zero, one, or two digits (so, for example, \exz matches a
659    binary zero character followed by z).
660  .sp  .sp
661    PCRE_MULTILINE    PCRE_MULTILINE
662  .sp  .sp
# Line 883  If studying the pattern does not produce Line 902  If studying the pattern does not produce
902  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
903  \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.
904  .P  .P
905  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
906  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
907  compiler is available, the pattern is further compiled into machine code that  compiler is available, the pattern is further compiled into machine code that
908  executes much faster than the \fBpcre_exec()\fP matching function. If  executes much faster than the \fBpcre_exec()\fP matching function. If
909  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
910  bits in the \fIoptions\fP argument must be zero.  bits in the \fIoptions\fP argument must be zero.
911  .P  .P
912  JIT compilation is a heavyweight optimization. It can take some time for  JIT compilation is a heavyweight optimization. It can take some time for
913  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
914  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.
915  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
916  handled, matching automatically falls back to the \fBpcre_exec()\fP  handled, matching automatically falls back to the \fBpcre_exec()\fP
917  interpreter. For more details, see the  interpreter. For more details, see the
918  .\" HREF  .\" HREF
# Line 915  API for release 8.20. For earlier versio Line 934  API for release 8.20. For earlier versio
934  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
935  new function when convenient.  new function when convenient.
936  .P  .P
937  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
938  real application there should be tests for errors):  real application there should be tests for errors):
939  .sp  .sp
940    int rc;    int rc;
# Line 927  real application there should be tests f Line 946  real application there should be tests f
946      0,              /* no options */      0,              /* no options */
947      &error);        /* set to NULL or points to a message */      &error);        /* set to NULL or points to a message */
948    rc = pcre_exec(   /* see below for details of pcre_exec() options */    rc = pcre_exec(   /* see below for details of pcre_exec() options */
949      re, sd, "subject", 7, 0, 0, ovector, 30);      re, sd, "subject", 7, 0, 0, ovector, 30);
950    ...    ...
951    pcre_free_study(sd);    pcre_free_study(sd);
952    pcre_free(re);    pcre_free(re);
953  .sp  .sp
954  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
955  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 964  single fixed starting character. A bitma
964  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
965  matching.  matching.
966  .P  .P
967  These two optimizations apply to both \fBpcre_exec()\fP and  These two optimizations apply to both \fBpcre_exec()\fP and
968  \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
969  \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
970  just-in-time compiling is successful. The optimizations can be disabled by  just-in-time compiling is successful. The optimizations can be disabled by
971  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 1136  Return 1 if the (?J) or (?-J) option set
1136  .sp  .sp
1137    PCRE_INFO_JIT    PCRE_INFO_JIT
1138  .sp  .sp
1139  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
1140  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
1141  \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
1142  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
1143  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
1144  particular pattern. See the  particular pattern. See the
1145  .\" HREF  .\" HREF
1146  \fBpcrejit\fP  \fBpcrejit\fP
# Line 1326  is different. (This seems a highly unlik Line 1345  is different. (This seems a highly unlik
1345  The function \fBpcre_exec()\fP is called to match a subject string against a  The function \fBpcre_exec()\fP is called to match a subject string against a
1346  compiled pattern, which is passed in the \fIcode\fP argument. If the  compiled pattern, which is passed in the \fIcode\fP argument. If the
1347  pattern was studied, the result of the study should be passed in the  pattern was studied, the result of the study should be passed in the
1348  \fIextra\fP argument. This function is the main matching facility of the  \fIextra\fP argument. You can call \fBpcre_exec()\fP with the same \fIcode\fP
1349  library, and it operates in a Perl-like manner. For specialist use there is  and \fIextra\fP arguments as many times as you like, in order to match
1350  also an alternative matching function, which is described  different subject strings with the same pattern.
1351    .P
1352    This function is the main matching facility of the library, and it operates in
1353    a Perl-like manner. For specialist use there is also an alternative matching
1354    function, which is described
1355  .\" HTML <a href="#dfamatch">  .\" HTML <a href="#dfamatch">
1356  .\" </a>  .\" </a>
1357  below  below
# Line 1372  fields (not necessarily in this order): Line 1395  fields (not necessarily in this order):
1395  .sp  .sp
1396    unsigned long int \fIflags\fP;    unsigned long int \fIflags\fP;
1397    void *\fIstudy_data\fP;    void *\fIstudy_data\fP;
1398    void *\fIexecutable_jit\fP;    void *\fIexecutable_jit\fP;
1399    unsigned long int \fImatch_limit\fP;    unsigned long int \fImatch_limit\fP;
1400    unsigned long int \fImatch_limit_recursion\fP;    unsigned long int \fImatch_limit_recursion\fP;
1401    void *\fIcallout_data\fP;    void *\fIcallout_data\fP;
# Line 1383  The \fIflags\fP field is a bitmap that s Line 1406  The \fIflags\fP field is a bitmap that s
1406  are set. The flag bits are:  are set. The flag bits are:
1407  .sp  .sp
1408    PCRE_EXTRA_STUDY_DATA    PCRE_EXTRA_STUDY_DATA
1409    PCRE_EXTRA_EXECUTABLE_JIT    PCRE_EXTRA_EXECUTABLE_JIT
1410    PCRE_EXTRA_MATCH_LIMIT    PCRE_EXTRA_MATCH_LIMIT
1411    PCRE_EXTRA_MATCH_LIMIT_RECURSION    PCRE_EXTRA_MATCH_LIMIT_RECURSION
1412    PCRE_EXTRA_CALLOUT_DATA    PCRE_EXTRA_CALLOUT_DATA
# Line 1406  calls repeatedly (sometimes recursively) Line 1429  calls repeatedly (sometimes recursively)
1429  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
1430  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
1431  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
1432  in the subject string.  in the subject string.
1433  .P  .P
1434  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
1435  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
1436  is entirely different. However, there is still the possibility of runaway  is entirely different. However, there is still the possibility of runaway
1437  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
1438  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
1439  matching can continue.  matching can continue.
# Line 1426  The \fImatch_limit_recursion\fP field is Line 1449  The \fImatch_limit_recursion\fP field is
1449  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
1450  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
1451  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.
1452  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.
1453  .P  .P
1454  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
1455  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
1456  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,
1457  is ignored, when the pattern was successfully studied with  and is ignored, if the pattern was successfully studied with
1458  PCRE_STUDY_JIT_COMPILE.  PCRE_STUDY_JIT_COMPILE.
1459  .P  .P
1460  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 1514  zero. The only bits that may be set are
1514  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,
1515  PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_SOFT, and  PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_SOFT, and
1516  PCRE_PARTIAL_HARD.  PCRE_PARTIAL_HARD.
1517    .P
1518    If the pattern was successfully studied with the PCRE_STUDY_JIT_COMPILE option,
1519    the only supported options for JIT execution are PCRE_NO_UTF8_CHECK,
1520    PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NOTEMPTY_ATSTART. Note in
1521    particular that partial matching is not supported. If an unsupported option is
1522    used, JIT execution is disabled and the normal interpretive code in
1523    \fBpcre_exec()\fP is run.
1524  .sp  .sp
1525    PCRE_ANCHORED    PCRE_ANCHORED
1526  .sp  .sp
# Line 1797  string that it matched that is returned. Line 1827  string that it matched that is returned.
1827  .P  .P
1828  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
1829  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
1830  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
1831  \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
1832  \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
1833  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
1834  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
1835  advisable to supply an \fIovector\fP.  is usually advisable to supply an \fIovector\fP of reasonable size.
1836    .P
1837    There are some cases where zero is returned (indicating vector overflow) when
1838    in fact the vector is exactly the right size for the final match. For example,
1839    consider the pattern
1840    .sp
1841      (a)(?:(b)c|bd)
1842    .sp
1843    If a vector of 6 elements (allowing for only 1 captured substring) is given
1844    with subject string "abd", \fBpcre_exec()\fP will try to set the second
1845    captured string, thereby recording a vector overflow, before failing to match
1846    "c" and backing up to try the second alternative. The zero return, however,
1847    does correctly indicate that the maximum number of slots (namely 2) have been
1848    filled. In similar cases where there is temporary overflow, but the final
1849    number of used slots is actually less than the maximum, a non-zero value is
1850    returned.
1851  .P  .P
1852  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
1853  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 1868  return from the function is 2, because t
1868  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
1869  (assuming the vector is large enough, of course) are set to -1.  (assuming the vector is large enough, of course) are set to -1.
1870  .P  .P
1871  \fBNote\fP: Elements of \fIovector\fP that do not correspond to capturing  \fBNote\fP: Elements in the first two-thirds of \fIovector\fP that do not
1872  parentheses in the pattern are never changed. That is, if a pattern contains  correspond to capturing parentheses in the pattern are never changed. That is,
1873  \fIn\fP capturing parentheses, no more than \fIovector[0]\fP to  if a pattern contains \fIn\fP capturing parentheses, no more than
1874  \fIovector[2n+1]\fP are set by \fBpcre_exec()\fP. The other elements retain  \fIovector[0]\fP to \fIovector[2n+1]\fP are set by \fBpcre_exec()\fP. The other
1875  whatever values they previously had.  elements (in the first two-thirds) retain whatever values they previously had.
1876  .P  .P
1877  Some convenience functions are provided for extracting the captured substrings  Some convenience functions are provided for extracting the captured substrings
1878  as separate strings. These are described below.  as separate strings. These are described below.
# Line 1982  time. Line 2027  time.
2027  .sp  .sp
2028    PCRE_ERROR_JIT_STACKLIMIT (-27)    PCRE_ERROR_JIT_STACKLIMIT (-27)
2029  .sp  .sp
2030  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
2031  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
2032  just-in-time processing stack is not large enough. See the  the just-in-time processing stack is not large enough. See the
2033  .\" HREF  .\" HREF
2034  \fBpcrejit\fP  \fBpcrejit\fP
2035  .\"  .\"
2036  documentation for more details.  documentation for more details.
2037  .P  .P
2038  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.
2039  .  .
# Line 2229  names are not included in the compiled c Line 2274  names are not included in the compiled c
2274  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
2275  same number causes an error at compile time.  same number causes an error at compile time.
2276  .  .
2277    .
2278  .SH "DUPLICATE SUBPATTERN NAMES"  .SH "DUPLICATE SUBPATTERN NAMES"
2279  .rs  .rs
2280  .sp  .sp
# Line 2428  returns data, even though the meaning of Line 2474  returns data, even though the meaning of
2474  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
2475  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
2476  \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
2477  the longest matches.  the longest matches. Unlike \fBpcre_exec()\fP, \fBpcre_dfa_exec()\fP can use
2478    the entire \fIovector\fP for returning matched strings.
2479  .  .
2480  .  .
2481  .SS "Error returns from \fBpcre_dfa_exec()\fP"  .SS "Error returns from \fBpcre_dfa_exec()\fP"
# Line 2497  Cambridge CB2 3QH, England. Line 2544  Cambridge CB2 3QH, England.
2544  .rs  .rs
2545  .sp  .sp
2546  .nf  .nf
2547  Last updated: 27 August 2011  Last updated: 14 November 2011
2548  Copyright (c) 1997-2011 University of Cambridge.  Copyright (c) 1997-2011 University of Cambridge.
2549  .fi  .fi

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