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diff --git a/external-libs/pcre/doc/pcreposix.3 b/external-libs/pcre/doc/pcreposix.3 deleted file mode 100644 index 5198630f..00000000 --- a/external-libs/pcre/doc/pcreposix.3 +++ /dev/null @@ -1,194 +0,0 @@ -.TH PCRE 3 -.SH NAME -PCRE - Perl-compatible regular expressions. -.SH SYNOPSIS OF POSIX API -.B #include <pcreposix.h> -.PP -.SM -.br -.B int regcomp(regex_t *\fIpreg\fR, const char *\fIpattern\fR, -.ti +5n -.B int \fIcflags\fR); -.PP -.br -.B int regexec(regex_t *\fIpreg\fR, const char *\fIstring\fR, -.ti +5n -.B size_t \fInmatch\fR, regmatch_t \fIpmatch\fR[], int \fIeflags\fR); -.PP -.br -.B size_t regerror(int \fIerrcode\fR, const regex_t *\fIpreg\fR, -.ti +5n -.B char *\fIerrbuf\fR, size_t \fIerrbuf_size\fR); -.PP -.br -.B void regfree(regex_t *\fIpreg\fR); - -.SH DESCRIPTION -.rs -.sp -This set of functions provides a POSIX-style API to the PCRE regular expression -package. See the -.\" HREF -\fBpcreapi\fR -.\" -documentation for a description of the native API, which contains additional -functionality. - -The functions described here are just wrapper functions that ultimately call -the PCRE native API. Their prototypes are defined in the \fBpcreposix.h\fR -header file, and on Unix systems the library itself is called -\fBpcreposix.a\fR, so can be accessed by adding \fB-lpcreposix\fR to the -command for linking an application which uses them. Because the POSIX functions -call the native ones, it is also necessary to add \fR-lpcre\fR. - -I have implemented only those option bits that can be reasonably mapped to PCRE -native options. In addition, the options REG_EXTENDED and REG_NOSUB are defined -with the value zero. They have no effect, but since programs that are written -to the POSIX interface often use them, this makes it easier to slot in PCRE as -a replacement library. Other POSIX options are not even defined. - -When PCRE is called via these functions, it is only the API that is POSIX-like -in style. The syntax and semantics of the regular expressions themselves are -still those of Perl, subject to the setting of various PCRE options, as -described below. "POSIX-like in style" means that the API approximates to the -POSIX definition; it is not fully POSIX-compatible, and in multi-byte encoding -domains it is probably even less compatible. - -The header for these functions is supplied as \fBpcreposix.h\fR to avoid any -potential clash with other POSIX libraries. It can, of course, be renamed or -aliased as \fBregex.h\fR, which is the "correct" name. It provides two -structure types, \fIregex_t\fR for compiled internal forms, and -\fIregmatch_t\fR for returning captured substrings. It also defines some -constants whose names start with "REG_"; these are used for setting options and -identifying error codes. - -.SH COMPILING A PATTERN -.rs -.sp -The function \fBregcomp()\fR is called to compile a pattern into an -internal form. The pattern is a C string terminated by a binary zero, and -is passed in the argument \fIpattern\fR. The \fIpreg\fR argument is a pointer -to a regex_t structure which is used as a base for storing information about -the compiled expression. - -The argument \fIcflags\fR is either zero, or contains one or more of the bits -defined by the following macros: - - REG_ICASE - -The PCRE_CASELESS option is set when the expression is passed for compilation -to the native function. - - REG_NEWLINE - -The PCRE_MULTILINE option is set when the expression is passed for compilation -to the native function. Note that this does \fInot\fR mimic the defined POSIX -behaviour for REG_NEWLINE (see the following section). - -In the absence of these flags, no options are passed to the native function. -This means the the regex is compiled with PCRE default semantics. In -particular, the way it handles newline characters in the subject string is the -Perl way, not the POSIX way. Note that setting PCRE_MULTILINE has only -\fIsome\fR of the effects specified for REG_NEWLINE. It does not affect the way -newlines are matched by . (they aren't) or by a negative class such as [^a] -(they are). - -The yield of \fBregcomp()\fR is zero on success, and non-zero otherwise. The -\fIpreg\fR structure is filled in on success, and one member of the structure -is public: \fIre_nsub\fR contains the number of capturing subpatterns in -the regular expression. Various error codes are defined in the header file. - -.SH MATCHING NEWLINE CHARACTERS -.rs -.sp -This area is not simple, because POSIX and Perl take different views of things. -It is not possible to get PCRE to obey POSIX semantics, but then PCRE was never -intended to be a POSIX engine. The following table lists the different -possibilities for matching newline characters in PCRE: - - Default Change with - - . matches newline no PCRE_DOTALL - newline matches [^a] yes not changeable - $ matches \\n at end yes PCRE_DOLLARENDONLY - $ matches \\n in middle no PCRE_MULTILINE - ^ matches \\n in middle no PCRE_MULTILINE - -This is the equivalent table for POSIX: - - Default Change with - - . matches newline yes REG_NEWLINE - newline matches [^a] yes REG_NEWLINE - $ matches \\n at end no REG_NEWLINE - $ matches \\n in middle no REG_NEWLINE - ^ matches \\n in middle no REG_NEWLINE - -PCRE's behaviour is the same as Perl's, except that there is no equivalent for -PCRE_DOLLARENDONLY in Perl. In both PCRE and Perl, there is no way to stop -newline from matching [^a]. - -The default POSIX newline handling can be obtained by setting PCRE_DOTALL and -PCRE_DOLLARENDONLY, but there is no way to make PCRE behave exactly as for the -REG_NEWLINE action. - -.SH MATCHING A PATTERN -.rs -.sp -The function \fBregexec()\fR is called to match a pre-compiled pattern -\fIpreg\fR against a given \fIstring\fR, which is terminated by a zero byte, -subject to the options in \fIeflags\fR. These can be: - - REG_NOTBOL - -The PCRE_NOTBOL option is set when calling the underlying PCRE matching -function. - - REG_NOTEOL - -The PCRE_NOTEOL option is set when calling the underlying PCRE matching -function. - -The portion of the string that was matched, and also any captured substrings, -are returned via the \fIpmatch\fR argument, which points to an array of -\fInmatch\fR structures of type \fIregmatch_t\fR, containing the members -\fIrm_so\fR and \fIrm_eo\fR. These contain the offset to the first character of -each substring and the offset to the first character after the end of each -substring, respectively. The 0th element of the vector relates to the entire -portion of \fIstring\fR that was matched; subsequent elements relate to the -capturing subpatterns of the regular expression. Unused entries in the array -have both structure members set to -1. - -A successful match yields a zero return; various error codes are defined in the -header file, of which REG_NOMATCH is the "expected" failure code. - -.SH ERROR MESSAGES -.rs -.sp -The \fBregerror()\fR function maps a non-zero errorcode from either -\fBregcomp()\fR or \fBregexec()\fR to a printable message. If \fIpreg\fR is not -NULL, the error should have arisen from the use of that structure. A message -terminated by a binary zero is placed in \fIerrbuf\fR. The length of the -message, including the zero, is limited to \fIerrbuf_size\fR. The yield of the -function is the size of buffer needed to hold the whole message. - -.SH STORAGE -.rs -.sp -Compiling a regular expression causes memory to be allocated and associated -with the \fIpreg\fR structure. The function \fBregfree()\fR frees all such -memory, after which \fIpreg\fR may no longer be used as a compiled expression. - -.SH AUTHOR -.rs -.sp -Philip Hazel <ph10@cam.ac.uk> -.br -University Computing Service, -.br -Cambridge CB2 3QG, England. - -.in 0 -Last updated: 03 February 2003 -.br -Copyright (c) 1997-2003 University of Cambridge. |