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revision 686 by ph10, Tue Sep 6 16:06:36 2011 UTC revision 776 by ph10, Thu Dec 1 11:02:56 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 315  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 365  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 643  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 888  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 920  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 932  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 950  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 1122  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 1248  For such patterns, the PCRE_ANCHORED bit Line 1262  For such patterns, the PCRE_ANCHORED bit
1262  .sp  .sp
1263    PCRE_INFO_SIZE    PCRE_INFO_SIZE
1264  .sp  .sp
1265  Return the size of the compiled pattern, that is, the value that was passed as  Return the size of the compiled pattern. The fourth argument should point to a
1266  the argument to \fBpcre_malloc()\fP when PCRE was getting memory in which to  \fBsize_t\fP variable. This value does not include the size of the \fBpcre\fP
1267  place the compiled data. The fourth argument should point to a \fBsize_t\fP  structure that is returned by \fBpcre_compile()\fP. The value that is passed as
1268  variable.  the argument to \fBpcre_malloc()\fP when \fBpcre_compile()\fP is getting memory
1269    in which to place the compiled data is the value returned by this option plus
1270    the size of the \fBpcre\fP structure. Studying a compiled pattern, with or
1271    without JIT, does not alter the value returned by this option.
1272  .sp  .sp
1273    PCRE_INFO_STUDYSIZE    PCRE_INFO_STUDYSIZE
1274  .sp  .sp
# Line 1331  is different. (This seems a highly unlik Line 1348  is different. (This seems a highly unlik
1348  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
1349  compiled pattern, which is passed in the \fIcode\fP argument. If the  compiled pattern, which is passed in the \fIcode\fP argument. If the
1350  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
1351  \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
1352  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
1353  also an alternative matching function, which is described  different subject strings with the same pattern.
1354    .P
1355    This function is the main matching facility of the library, and it operates in
1356    a Perl-like manner. For specialist use there is also an alternative matching
1357    function, which is described
1358  .\" HTML <a href="#dfamatch">  .\" HTML <a href="#dfamatch">
1359  .\" </a>  .\" </a>
1360  below  below
# Line 1377  fields (not necessarily in this order): Line 1398  fields (not necessarily in this order):
1398  .sp  .sp
1399    unsigned long int \fIflags\fP;    unsigned long int \fIflags\fP;
1400    void *\fIstudy_data\fP;    void *\fIstudy_data\fP;
1401    void *\fIexecutable_jit\fP;    void *\fIexecutable_jit\fP;
1402    unsigned long int \fImatch_limit\fP;    unsigned long int \fImatch_limit\fP;
1403    unsigned long int \fImatch_limit_recursion\fP;    unsigned long int \fImatch_limit_recursion\fP;
1404    void *\fIcallout_data\fP;    void *\fIcallout_data\fP;
# Line 1388  The \fIflags\fP field is a bitmap that s Line 1409  The \fIflags\fP field is a bitmap that s
1409  are set. The flag bits are:  are set. The flag bits are:
1410  .sp  .sp
1411    PCRE_EXTRA_STUDY_DATA    PCRE_EXTRA_STUDY_DATA
1412    PCRE_EXTRA_EXECUTABLE_JIT    PCRE_EXTRA_EXECUTABLE_JIT
1413    PCRE_EXTRA_MATCH_LIMIT    PCRE_EXTRA_MATCH_LIMIT
1414    PCRE_EXTRA_MATCH_LIMIT_RECURSION    PCRE_EXTRA_MATCH_LIMIT_RECURSION
1415    PCRE_EXTRA_CALLOUT_DATA    PCRE_EXTRA_CALLOUT_DATA
# Line 1411  calls repeatedly (sometimes recursively) Line 1432  calls repeatedly (sometimes recursively)
1432  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
1433  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
1434  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
1435  in the subject string.  in the subject string.
1436  .P  .P
1437  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
1438  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
1439  is entirely different. However, there is still the possibility of runaway  is entirely different. However, there is still the possibility of runaway
1440  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
1441  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
1442  matching can continue.  matching can continue.
# Line 1431  The \fImatch_limit_recursion\fP field is Line 1452  The \fImatch_limit_recursion\fP field is
1452  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
1453  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
1454  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.
1455  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.
1456  .P  .P
1457  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
1458  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
# Line 1500  PCRE_PARTIAL_HARD. Line 1521  PCRE_PARTIAL_HARD.
1521  If the pattern was successfully studied with the PCRE_STUDY_JIT_COMPILE option,  If the pattern was successfully studied with the PCRE_STUDY_JIT_COMPILE option,
1522  the only supported options for JIT execution are PCRE_NO_UTF8_CHECK,  the only supported options for JIT execution are PCRE_NO_UTF8_CHECK,
1523  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NOTEMPTY_ATSTART. Note in  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NOTEMPTY_ATSTART. Note in
1524  particular that partial matching is not supported. If an unsupported option is  particular that partial matching is not supported. If an unsupported option is
1525  used, JIT execution is disabled and the normal interpretive code in  used, JIT execution is disabled and the normal interpretive code in
1526  \fBpcre_exec()\fP is run.  \fBpcre_exec()\fP is run.
1527  .sp  .sp
1528    PCRE_ANCHORED    PCRE_ANCHORED
# Line 1825  consider the pattern Line 1846  consider the pattern
1846  If a vector of 6 elements (allowing for only 1 captured substring) is given  If a vector of 6 elements (allowing for only 1 captured substring) is given
1847  with subject string "abd", \fBpcre_exec()\fP will try to set the second  with subject string "abd", \fBpcre_exec()\fP will try to set the second
1848  captured string, thereby recording a vector overflow, before failing to match  captured string, thereby recording a vector overflow, before failing to match
1849  "c" and backing up to try the second alternative. The zero return, however,  "c" and backing up to try the second alternative. The zero return, however,
1850  does correctly indicate that the maximum number of slots (namely 2) have been  does correctly indicate that the maximum number of slots (namely 2) have been
1851  filled. In similar cases where there is temporary overflow, but the final  filled. In similar cases where there is temporary overflow, but the final
1852  number of used slots is actually less than the maximum, a non-zero value is  number of used slots is actually less than the maximum, a non-zero value is
# Line 2009  time. Line 2030  time.
2030  .sp  .sp
2031    PCRE_ERROR_JIT_STACKLIMIT (-27)    PCRE_ERROR_JIT_STACKLIMIT (-27)
2032  .sp  .sp
2033  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
2034  PCRE_STUDY_JIT_COMPILE option is being matched, but the memory available for  PCRE_STUDY_JIT_COMPILE option is being matched, but the memory available for
2035  the just-in-time processing stack is not large enough. See the  the just-in-time processing stack is not large enough. See the
2036  .\" HREF  .\" HREF
2037  \fBpcrejit\fP  \fBpcrejit\fP
2038  .\"  .\"
2039  documentation for more details.  documentation for more details.
2040  .P  .P
2041  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.
2042  .  .
# Line 2456  returns data, even though the meaning of Line 2477  returns data, even though the meaning of
2477  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
2478  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
2479  \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
2480  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
2481  the entire \fIovector\fP for returning matched strings.  the entire \fIovector\fP for returning matched strings.
2482  .  .
2483  .  .
# Line 2526  Cambridge CB2 3QH, England. Line 2547  Cambridge CB2 3QH, England.
2547  .rs  .rs
2548  .sp  .sp
2549  .nf  .nf
2550  Last updated: 06 September 2011  Last updated: 01 December 2011
2551  Copyright (c) 1997-2011 University of Cambridge.  Copyright (c) 1997-2011 University of Cambridge.
2552  .fi  .fi

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