--- embedaddon/pcre/doc/pcreapi.3 2013/07/22 08:25:56 1.1.1.4 +++ embedaddon/pcre/doc/pcreapi.3 2014/06/15 19:46:05 1.1.1.5 @@ -1,4 +1,4 @@ -.TH PCREAPI 3 "12 May 2013" "PCRE 8.33" +.TH PCREAPI 3 "12 November 2013" "PCRE 8.34" .SH NAME PCRE - Perl-compatible regular expressions .sp @@ -8,138 +8,115 @@ PCRE - Perl-compatible regular expressions .SH "PCRE NATIVE API BASIC FUNCTIONS" .rs .sp -.SM +.nf .B pcre *pcre_compile(const char *\fIpattern\fP, int \fIoptions\fP, -.ti +5n -.B const char **\fIerrptr\fP, int *\fIerroffset\fP, -.ti +5n -.B const unsigned char *\fItableptr\fP); -.PP +.B " const char **\fIerrptr\fP, int *\fIerroffset\fP," +.B " const unsigned char *\fItableptr\fP);" +.sp .B pcre *pcre_compile2(const char *\fIpattern\fP, int \fIoptions\fP, -.ti +5n -.B int *\fIerrorcodeptr\fP, -.ti +5n -.B const char **\fIerrptr\fP, int *\fIerroffset\fP, -.ti +5n -.B const unsigned char *\fItableptr\fP); -.PP +.B " int *\fIerrorcodeptr\fP," +.B " const char **\fIerrptr\fP, int *\fIerroffset\fP," +.B " const unsigned char *\fItableptr\fP);" +.sp .B pcre_extra *pcre_study(const pcre *\fIcode\fP, int \fIoptions\fP, -.ti +5n -.B const char **\fIerrptr\fP); -.PP +.B " const char **\fIerrptr\fP);" +.sp .B void pcre_free_study(pcre_extra *\fIextra\fP); -.PP +.sp .B int pcre_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP," -.ti +5n -.B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP, -.ti +5n -.B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP); -.PP +.B " const char *\fIsubject\fP, int \fIlength\fP, int \fIstartoffset\fP," +.B " int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);" +.sp .B int pcre_dfa_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP," -.ti +5n -.B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP, -.ti +5n -.B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP, -.ti +5n -.B int *\fIworkspace\fP, int \fIwscount\fP); +.B " const char *\fIsubject\fP, int \fIlength\fP, int \fIstartoffset\fP," +.B " int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP," +.B " int *\fIworkspace\fP, int \fIwscount\fP);" +.fi . . .SH "PCRE NATIVE API STRING EXTRACTION FUNCTIONS" .rs .sp +.nf .B int pcre_copy_named_substring(const pcre *\fIcode\fP, -.ti +5n -.B const char *\fIsubject\fP, int *\fIovector\fP, -.ti +5n -.B int \fIstringcount\fP, const char *\fIstringname\fP, -.ti +5n -.B char *\fIbuffer\fP, int \fIbuffersize\fP); -.PP +.B " const char *\fIsubject\fP, int *\fIovector\fP," +.B " int \fIstringcount\fP, const char *\fIstringname\fP," +.B " char *\fIbuffer\fP, int \fIbuffersize\fP);" +.sp .B int pcre_copy_substring(const char *\fIsubject\fP, int *\fIovector\fP, -.ti +5n -.B int \fIstringcount\fP, int \fIstringnumber\fP, char *\fIbuffer\fP, -.ti +5n -.B int \fIbuffersize\fP); -.PP +.B " int \fIstringcount\fP, int \fIstringnumber\fP, char *\fIbuffer\fP," +.B " int \fIbuffersize\fP);" +.sp .B int pcre_get_named_substring(const pcre *\fIcode\fP, -.ti +5n -.B const char *\fIsubject\fP, int *\fIovector\fP, -.ti +5n -.B int \fIstringcount\fP, const char *\fIstringname\fP, -.ti +5n -.B const char **\fIstringptr\fP); -.PP +.B " const char *\fIsubject\fP, int *\fIovector\fP," +.B " int \fIstringcount\fP, const char *\fIstringname\fP," +.B " const char **\fIstringptr\fP);" +.sp .B int pcre_get_stringnumber(const pcre *\fIcode\fP, -.ti +5n -.B const char *\fIname\fP); -.PP +.B " const char *\fIname\fP);" +.sp .B int pcre_get_stringtable_entries(const pcre *\fIcode\fP, -.ti +5n -.B const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP); -.PP +.B " const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP);" +.sp .B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP, -.ti +5n -.B int \fIstringcount\fP, int \fIstringnumber\fP, -.ti +5n -.B const char **\fIstringptr\fP); -.PP +.B " int \fIstringcount\fP, int \fIstringnumber\fP," +.B " const char **\fIstringptr\fP);" +.sp .B int pcre_get_substring_list(const char *\fIsubject\fP, -.ti +5n -.B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);" -.PP +.B " int *\fIovector\fP, int \fIstringcount\fP, const char ***\fIlistptr\fP);" +.sp .B void pcre_free_substring(const char *\fIstringptr\fP); -.PP +.sp .B void pcre_free_substring_list(const char **\fIstringptr\fP); +.fi . . .SH "PCRE NATIVE API AUXILIARY FUNCTIONS" .rs .sp +.nf .B int pcre_jit_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP," -.ti +5n -.B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP, -.ti +5n -.B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP, -.ti +5n -.B pcre_jit_stack *\fIjstack\fP); -.PP +.B " const char *\fIsubject\fP, int \fIlength\fP, int \fIstartoffset\fP," +.B " int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP," +.B " pcre_jit_stack *\fIjstack\fP);" +.sp .B pcre_jit_stack *pcre_jit_stack_alloc(int \fIstartsize\fP, int \fImaxsize\fP); -.PP +.sp .B void pcre_jit_stack_free(pcre_jit_stack *\fIstack\fP); -.PP +.sp .B void pcre_assign_jit_stack(pcre_extra *\fIextra\fP, -.ti +5n -.B pcre_jit_callback \fIcallback\fP, void *\fIdata\fP); -.PP +.B " pcre_jit_callback \fIcallback\fP, void *\fIdata\fP);" +.sp .B const unsigned char *pcre_maketables(void); -.PP +.sp .B int pcre_fullinfo(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP," -.ti +5n -.B int \fIwhat\fP, void *\fIwhere\fP); -.PP +.B " int \fIwhat\fP, void *\fIwhere\fP);" +.sp .B int pcre_refcount(pcre *\fIcode\fP, int \fIadjust\fP); -.PP +.sp .B int pcre_config(int \fIwhat\fP, void *\fIwhere\fP); -.PP +.sp .B const char *pcre_version(void); -.PP +.sp .B int pcre_pattern_to_host_byte_order(pcre *\fIcode\fP, -.ti +5n -.B pcre_extra *\fIextra\fP, const unsigned char *\fItables\fP); +.B " pcre_extra *\fIextra\fP, const unsigned char *\fItables\fP);" +.fi . . .SH "PCRE NATIVE API INDIRECTED FUNCTIONS" .rs .sp +.nf .B void *(*pcre_malloc)(size_t); -.PP +.sp .B void (*pcre_free)(void *); -.PP +.sp .B void *(*pcre_stack_malloc)(size_t); -.PP +.sp .B void (*pcre_stack_free)(void *); -.PP +.sp .B int (*pcre_callout)(pcre_callout_block *); +.fi . . .SH "PCRE 8-BIT, 16-BIT, AND 32-BIT LIBRARIES" @@ -483,6 +460,13 @@ the .\" documentation. .sp + PCRE_CONFIG_PARENS_LIMIT +.sp +The output is a long integer that gives the maximum depth of nesting of +parentheses (of any kind) in a pattern. This limit is imposed to cap the amount +of system stack used when a pattern is compiled. It is specified when PCRE is +built; the default is 250. +.sp PCRE_CONFIG_MATCH_LIMIT .sp The output is a long integer that gives the default limit for the number of @@ -509,19 +493,16 @@ avoiding the use of the stack. .SH "COMPILING A PATTERN" .rs .sp +.nf .B pcre *pcre_compile(const char *\fIpattern\fP, int \fIoptions\fP, -.ti +5n -.B const char **\fIerrptr\fP, int *\fIerroffset\fP, -.ti +5n -.B const unsigned char *\fItableptr\fP); +.B " const char **\fIerrptr\fP, int *\fIerroffset\fP," +.B " const unsigned char *\fItableptr\fP);" .sp .B pcre *pcre_compile2(const char *\fIpattern\fP, int \fIoptions\fP, -.ti +5n -.B int *\fIerrorcodeptr\fP, -.ti +5n -.B const char **\fIerrptr\fP, int *\fIerroffset\fP, -.ti +5n -.B const unsigned char *\fItableptr\fP); +.B " int *\fIerrorcodeptr\fP," +.B " const char **\fIerrptr\fP, int *\fIerroffset\fP," +.B " const unsigned char *\fItableptr\fP);" +.fi .P Either of the functions \fBpcre_compile()\fP or \fBpcre_compile2()\fP can be called to compile a pattern into an internal form. The only difference between @@ -581,8 +562,9 @@ If the final argument, \fItableptr\fP, is NULL, PCRE u character tables that are built when PCRE is compiled, using the default C locale. Otherwise, \fItableptr\fP must be an address that is the result of a call to \fBpcre_maketables()\fP. This value is stored with the compiled -pattern, and used again by \fBpcre_exec()\fP, unless another table pointer is -passed to it. For more discussion, see the section on locale support below. +pattern, and used again by \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP when the +pattern is matched. For more discussion, see the section on locale support +below. .P This code fragment shows a typical straightforward call to \fBpcre_compile()\fP: .sp @@ -670,13 +652,23 @@ documentation. .sp PCRE_EXTENDED .sp -If this bit is set, white space data characters in the pattern are totally -ignored except when escaped or inside a character class. White space does not -include the VT character (code 11). In addition, characters between an -unescaped # outside a character class and the next newline, inclusive, are also -ignored. This is equivalent to Perl's /x option, and it can be changed within a -pattern by a (?x) option setting. +If this bit is set, most white space characters in the pattern are totally +ignored except when escaped or inside a character class. However, white space +is not allowed within sequences such as (?> that introduce various +parenthesized subpatterns, nor within a numerical quantifier such as {1,3}. +However, ignorable white space is permitted between an item and a following +quantifier and between a quantifier and a following + that indicates +possessiveness. .P +White space did not used to include the VT character (code 11), because Perl +did not treat this character as white space. However, Perl changed at release +5.18, so PCRE followed at release 8.34, and VT is now treated as white space. +.P +PCRE_EXTENDED also causes characters between an unescaped # outside a character +class and the next newline, inclusive, to be ignored. PCRE_EXTENDED is +equivalent to Perl's /x option, and it can be changed within a pattern by a +(?x) option setting. +.P Which characters are interpreted as newlines is controlled by the options passed to \fBpcre_compile()\fP or by a special sequence at the start of the pattern, as described in the section entitled @@ -821,6 +813,15 @@ were followed by ?: but named parentheses can still be they acquire numbers in the usual way). There is no equivalent of this option in Perl. .sp + PCRE_NO_AUTO_POSSESS +.sp +If this option is set, it disables "auto-possessification". This is an +optimization that, for example, turns a+b into a++b in order to avoid +backtracks into a+ that can never be successful. However, if callouts are in +use, auto-possessification means that some of them are never taken. You can set +this option if you want the matching functions to do a full unoptimized search +and run all the callouts, but it is mainly provided for testing purposes. +.sp PCRE_NO_START_OPTIMIZE .sp This is an option that acts at matching time; that is, it is really an option @@ -886,10 +887,10 @@ page. If an invalid UTF-8 sequence is found, \fBpcre_c error. If you already know that your pattern is valid, and you want to skip this check for performance reasons, you can set the PCRE_NO_UTF8_CHECK option. When it is set, the effect of passing an invalid UTF-8 string as a pattern is -undefined. It may cause your program to crash. Note that this option can also -be passed to \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, to suppress the -validity checking of subject strings only. If the same string is being matched -many times, the option can be safely set for the second and subsequent +undefined. It may cause your program to crash or loop. Note that this option +can also be passed to \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, to suppress +the validity checking of subject strings only. If the same string is being +matched many times, the option can be safely set for the second and subsequent matchings to improve performance. . . @@ -936,7 +937,7 @@ have fallen out of use. To avoid confusion, they have 31 POSIX collating elements are not supported 32 this version of PCRE is compiled without UTF support 33 [this code is not in use] - 34 character value in \ex{...} sequence is too large + 34 character value in \ex{} or \eo{} is too large 35 invalid condition (?(0) 36 \eC not allowed in lookbehind assertion 37 PCRE does not support \eL, \el, \eN{name}, \eU, or \eu @@ -984,6 +985,12 @@ have fallen out of use. To avoid confusion, they have 75 name is too long in (*MARK), (*PRUNE), (*SKIP), or (*THEN) 76 character value in \eu.... sequence is too large 77 invalid UTF-32 string (specifically UTF-32) + 78 setting UTF is disabled by the application + 79 non-hex character in \ex{} (closing brace missing?) + 80 non-octal character in \eo{} (closing brace missing?) + 81 missing opening brace after \eo + 82 parentheses are too deeply nested + 83 invalid range in character class .sp The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may be used if the limits were changed when PCRE was built. @@ -993,9 +1000,10 @@ be used if the limits were changed when PCRE was built .SH "STUDYING A PATTERN" .rs .sp -.B pcre_extra *pcre_study(const pcre *\fIcode\fP, int \fIoptions\fP -.ti +5n -.B const char **\fIerrptr\fP); +.nf +.B pcre_extra *pcre_study(const pcre *\fIcode\fP, int \fIoptions\fP, +.B " const char **\fIerrptr\fP);" +.fi .PP If a compiled pattern is going to be used several times, it is worth spending more time analyzing it in order to speed up the time taken for matching. The @@ -1117,16 +1125,18 @@ below. .sp PCRE handles caseless matching, and determines whether characters are letters, digits, or whatever, by reference to a set of tables, indexed by character -value. When running in UTF-8 mode, this applies only to characters -with codes less than 128. By default, higher-valued codes never match escapes -such as \ew or \ed, but they can be tested with \ep if PCRE is built with -Unicode character property support. Alternatively, the PCRE_UCP option can be -set at compile time; this causes \ew and friends to use Unicode property -support instead of built-in tables. The use of locales with Unicode is -discouraged. If you are handling characters with codes greater than 128, you -should either use UTF-8 and Unicode, or use locales, but not try to mix the -two. +code point. When running in UTF-8 mode, or in the 16- or 32-bit libraries, this +applies only to characters with code points less than 256. By default, +higher-valued code points never match escapes such as \ew or \ed. However, if +PCRE is built with Unicode property support, all characters can be tested with +\ep and \eP, or, alternatively, the PCRE_UCP option can be set when a pattern +is compiled; this causes \ew and friends to use Unicode property support +instead of the built-in tables. .P +The use of locales with Unicode is discouraged. If you are handling characters +with code points greater than 128, you should either use Unicode support, or +use locales, but not try to mix the two. +.P PCRE contains an internal set of tables that are used when the final argument of \fBpcre_compile()\fP is NULL. These are sufficient for many applications. Normally, the internal tables recognize only ASCII characters. However, when @@ -1140,10 +1150,10 @@ for this locale support is expected to die away. .P External tables are built by calling the \fBpcre_maketables()\fP function, which has no arguments, in the relevant locale. The result can then be passed -to \fBpcre_compile()\fP or \fBpcre_exec()\fP as often as necessary. For -example, to build and use tables that are appropriate for the French locale -(where accented characters with values greater than 128 are treated as letters), -the following code could be used: +to \fBpcre_compile()\fP as often as necessary. For example, to build and use +tables that are appropriate for the French locale (where accented characters +with values greater than 128 are treated as letters), the following code could +be used: .sp setlocale(LC_CTYPE, "fr_FR"); tables = pcre_maketables(); @@ -1159,24 +1169,29 @@ needed. .P The pointer that is passed to \fBpcre_compile()\fP is saved with the compiled pattern, and the same tables are used via this pointer by \fBpcre_study()\fP -and normally also by \fBpcre_exec()\fP. Thus, by default, for any single +and also by \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP. Thus, for any single pattern, compilation, studying and matching all happen in the same locale, but -different patterns can be compiled in different locales. +different patterns can be processed in different locales. .P It is possible to pass a table pointer or NULL (indicating the use of the -internal tables) to \fBpcre_exec()\fP. Although not intended for this purpose, -this facility could be used to match a pattern in a different locale from the -one in which it was compiled. Passing table pointers at run time is discussed -below in the section on matching a pattern. +internal tables) to \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP (see the +discussion below in the section on matching a pattern). This facility is +provided for use with pre-compiled patterns that have been saved and reloaded. +Character tables are not saved with patterns, so if a non-standard table was +used at compile time, it must be provided again when the reloaded pattern is +matched. Attempting to use this facility to match a pattern in a different +locale from the one in which it was compiled is likely to lead to anomalous +(usually incorrect) results. . . .\" HTML .SH "INFORMATION ABOUT A PATTERN" .rs .sp +.nf .B int pcre_fullinfo(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP," -.ti +5n -.B int \fIwhat\fP, void *\fIwhere\fP); +.B " int \fIwhat\fP, void *\fIwhere\fP);" +.fi .PP The \fBpcre_fullinfo()\fP function returns information about a compiled pattern. It replaces the \fBpcre_info()\fP function, which was removed from the @@ -1310,10 +1325,15 @@ only if it follows something of variable length. For e is -1. .P Since for the 32-bit library using the non-UTF-32 mode, this function is unable -to return the full 32-bit range of the character, this value is deprecated; +to return the full 32-bit range of characters, this value is deprecated; instead the PCRE_INFO_REQUIREDCHARFLAGS and PCRE_INFO_REQUIREDCHAR values should be used. .sp + PCRE_INFO_MATCH_EMPTY +.sp +Return 1 if the pattern can match an empty string, otherwise 0. The fourth +argument should point to an \fBint\fP variable. +.sp PCRE_INFO_MATCHLIMIT .sp If the pattern set a match limit by including an item of the form @@ -1369,8 +1389,8 @@ most significant byte first. In the 16-bit library, th contains the parenthesis number. The rest of the entry is the corresponding name, zero terminated. .P -The names are in alphabetical order. Duplicate names may appear if (?| is used -to create multiple groups with the same number, as described in the +The names are in alphabetical order. If (?| is used to create multiple groups +with the same number, as described in the .\" HTML .\" section on duplicate subpattern numbers @@ -1379,11 +1399,13 @@ in the .\" HREF \fBpcrepattern\fP .\" -page. Duplicate names for subpatterns with different numbers are permitted only -if PCRE_DUPNAMES is set. In all cases of duplicate names, they appear in the -table in the order in which they were found in the pattern. In the absence of -(?| this is the order of increasing number; when (?| is used this is not -necessarily the case because later subpatterns may have lower numbers. +page, the groups may be given the same name, but there is only one entry in the +table. Different names for groups of the same number are not permitted. +Duplicate names for subpatterns with different numbers are permitted, +but only if PCRE_DUPNAMES is set. They appear in the table in the order in +which they were found in the pattern. In the absence of (?| this is the order +of increasing number; when (?| is used this is not necessarily the case because +later subpatterns may have lower numbers. .P As a simple example of the name/number table, consider the following pattern after compilation by the 8-bit library (assume PCRE_EXTENDED is set, so white @@ -1501,26 +1523,14 @@ returned. For anchored patterns, 0 is returned. .sp PCRE_INFO_FIRSTCHARACTER .sp -Return the fixed first character value, if PCRE_INFO_FIRSTCHARACTERFLAGS -returned 1; otherwise returns 0. The fourth argument should point to an -\fBuint_t\fP variable. +Return the fixed first character value in the situation where +PCRE_INFO_FIRSTCHARACTERFLAGS returns 1; otherwise return 0. The fourth +argument should point to an \fBuint_t\fP variable. .P In the 8-bit library, the value is always less than 256. In the 16-bit library the value can be up to 0xffff. In the 32-bit library in UTF-32 mode the value can be up to 0x10ffff, and up to 0xffffffff when not using UTF-32 mode. -.P -If there is no fixed first value, and if either .sp -(a) the pattern was compiled with the PCRE_MULTILINE option, and every branch -starts with "^", or -.sp -(b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not set -(if it were set, the pattern would be anchored), -.sp --1 is returned, indicating that the pattern matches only at the start of a -subject string or after any newline within the string. Otherwise -2 is -returned. For anchored patterns, -2 is returned. -.sp PCRE_INFO_REQUIREDCHARFLAGS .sp Returns 1 if there is a rightmost literal data unit that must exist in any @@ -1567,11 +1577,11 @@ is different. (This seems a highly unlikely scenario.) .SH "MATCHING A PATTERN: THE TRADITIONAL FUNCTION" .rs .sp +.nf .B int pcre_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP," -.ti +5n -.B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP, -.ti +5n -.B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP); +.B " const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP, +.B " int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);" +.fi .P The function \fBpcre_exec()\fP is called to match a subject string against a compiled pattern, which is passed in the \fIcode\fP argument. If the @@ -1724,20 +1734,24 @@ and is described in the .\" documentation. .P -The \fItables\fP field is used to pass a character tables pointer to -\fBpcre_exec()\fP; this overrides the value that is stored with the compiled -pattern. A non-NULL value is stored with the compiled pattern only if custom -tables were supplied to \fBpcre_compile()\fP via its \fItableptr\fP argument. -If NULL is passed to \fBpcre_exec()\fP using this mechanism, it forces PCRE's -internal tables to be used. This facility is helpful when re-using patterns -that have been saved after compiling with an external set of tables, because -the external tables might be at a different address when \fBpcre_exec()\fP is -called. See the +The \fItables\fP field is provided for use with patterns that have been +pre-compiled using custom character tables, saved to disc or elsewhere, and +then reloaded, because the tables that were used to compile a pattern are not +saved with it. See the .\" HREF \fBpcreprecompile\fP .\" -documentation for a discussion of saving compiled patterns for later use. +documentation for a discussion of saving compiled patterns for later use. If +NULL is passed using this mechanism, it forces PCRE's internal tables to be +used. .P +\fBWarning:\fP The tables that \fBpcre_exec()\fP uses must be the same as those +that were used when the pattern was compiled. If this is not the case, the +behaviour of \fBpcre_exec()\fP is undefined. Therefore, when a pattern is +compiled and matched in the same process, this field should never be set. In +this (the most common) case, the correct table pointer is automatically passed +with the compiled pattern from \fBpcre_compile()\fP to \fBpcre_exec()\fP. +.P If PCRE_EXTRA_MARK is set in the \fIflags\fP field, the \fImark\fP field must be set to point to a suitable variable. If the pattern contains any backtracking control verbs such as (*MARK:NAME), and the execution ends up with @@ -1960,7 +1974,7 @@ all the matches in a single subject string. However, y the value of \fIstartoffset\fP points to the start of a character (or the end of the subject). When PCRE_NO_UTF8_CHECK is set, the effect of passing an invalid string as a subject or an invalid value of \fIstartoffset\fP is -undefined. Your program may crash. +undefined. Your program may crash or loop. .sp PCRE_PARTIAL_HARD PCRE_PARTIAL_SOFT @@ -2423,21 +2437,18 @@ no longer in use and is never returned. .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER" .rs .sp +.nf .B int pcre_copy_substring(const char *\fIsubject\fP, int *\fIovector\fP, -.ti +5n -.B int \fIstringcount\fP, int \fIstringnumber\fP, char *\fIbuffer\fP, -.ti +5n -.B int \fIbuffersize\fP); -.PP +.B " int \fIstringcount\fP, int \fIstringnumber\fP, char *\fIbuffer\fP," +.B " int \fIbuffersize\fP);" +.sp .B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP, -.ti +5n -.B int \fIstringcount\fP, int \fIstringnumber\fP, -.ti +5n -.B const char **\fIstringptr\fP); -.PP +.B " int \fIstringcount\fP, int \fIstringnumber\fP," +.B " const char **\fIstringptr\fP);" +.sp .B int pcre_get_substring_list(const char *\fIsubject\fP, -.ti +5n -.B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);" +.B " int *\fIovector\fP, int \fIstringcount\fP, const char ***\fIlistptr\fP);" +.fi .PP Captured substrings can be accessed directly by using the offsets returned by \fBpcre_exec()\fP in \fIovector\fP. For convenience, the functions @@ -2516,25 +2527,20 @@ provided. .SH "EXTRACTING CAPTURED SUBSTRINGS BY NAME" .rs .sp +.nf .B int pcre_get_stringnumber(const pcre *\fIcode\fP, -.ti +5n -.B const char *\fIname\fP); -.PP +.B " const char *\fIname\fP);" +.sp .B int pcre_copy_named_substring(const pcre *\fIcode\fP, -.ti +5n -.B const char *\fIsubject\fP, int *\fIovector\fP, -.ti +5n -.B int \fIstringcount\fP, const char *\fIstringname\fP, -.ti +5n -.B char *\fIbuffer\fP, int \fIbuffersize\fP); -.PP +.B " const char *\fIsubject\fP, int *\fIovector\fP," +.B " int \fIstringcount\fP, const char *\fIstringname\fP," +.B " char *\fIbuffer\fP, int \fIbuffersize\fP);" +.sp .B int pcre_get_named_substring(const pcre *\fIcode\fP, -.ti +5n -.B const char *\fIsubject\fP, int *\fIovector\fP, -.ti +5n -.B int \fIstringcount\fP, const char *\fIstringname\fP, -.ti +5n -.B const char **\fIstringptr\fP); +.B " const char *\fIsubject\fP, int *\fIovector\fP," +.B " int \fIstringcount\fP, const char *\fIstringname\fP," +.B " const char **\fIstringptr\fP);" +.fi .PP To extract a substring by name, you first have to find associated number. For example, for this pattern @@ -2586,9 +2592,10 @@ same number causes an error at compile time. .SH "DUPLICATE SUBPATTERN NAMES" .rs .sp +.nf .B int pcre_get_stringtable_entries(const pcre *\fIcode\fP, -.ti +5n -.B const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP); +.B " const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP);" +.fi .PP When a pattern is compiled with the PCRE_DUPNAMES option, names for subpatterns are not required to be unique. (Duplicate names are always allowed for @@ -2677,13 +2684,12 @@ the value returned is the size of each block that is o .SH "MATCHING A PATTERN: THE ALTERNATIVE FUNCTION" .rs .sp +.nf .B int pcre_dfa_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP," -.ti +5n -.B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP, -.ti +5n -.B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP, -.ti +5n -.B int *\fIworkspace\fP, int \fIwscount\fP); +.B " const char *\fIsubject\fP, int \fIlength\fP, int \fIstartoffset\fP," +.B " int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP," +.B " int *\fIworkspace\fP, int \fIwscount\fP);" +.fi .P The function \fBpcre_dfa_exec()\fP is called to match a subject string against a compiled pattern, using a matching algorithm that scans the subject string @@ -2810,6 +2816,14 @@ matching string is given first. If there were too many \fIovector\fP, the yield of the function is zero, and the vector is filled with the longest matches. Unlike \fBpcre_exec()\fP, \fBpcre_dfa_exec()\fP can use the entire \fIovector\fP for returning matched strings. +.P +NOTE: PCRE's "auto-possessification" optimization usually applies to character +repeats at the end of a pattern (as well as internally). For example, the +pattern "a\ed+" is compiled as if it were "a\ed++" because there is no point +even considering the possibility of backtracking into the repeated digits. For +DFA matching, this means that only one possible match is found. If you really +do want multiple matches in such cases, either use an ungreedy repeat +("a\ed+?") or set the PCRE_NO_AUTO_POSSESS option when compiling. . . .SS "Error returns from \fBpcre_dfa_exec()\fP" @@ -2886,6 +2900,6 @@ Cambridge CB2 3QH, England. .rs .sp .nf -Last updated: 12 May 2013 +Last updated: 12 November 2013 Copyright (c) 1997-2013 University of Cambridge. .fi