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Diffstat (limited to 'pcreposix.c')
| -rw-r--r-- | pcreposix.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/pcreposix.c b/pcreposix.c new file mode 100644 index 0000000..1fbd9ac --- /dev/null +++ b/pcreposix.c @@ -0,0 +1,246 @@ +/************************************************* +* Perl-Compatible Regular Expressions * +*************************************************/ + +/* +This is a library of functions to support regular expressions whose syntax +and semantics are as close as possible to those of the Perl 5 language. See +the file Tech.Notes for some information on the internals. + +This module is a wrapper that provides a POSIX API to the underlying PCRE +functions. + +Written by: Philip Hazel <ph10@cam.ac.uk> + + Copyright (c) 1997 University of Cambridge + +----------------------------------------------------------------------------- +Permission is granted to anyone to use this software for any purpose on any +computer system, and to redistribute it freely, subject to the following +restrictions: + +1. This software is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + +2. The origin of this software must not be misrepresented, either by + explicit claim or by omission. + +3. Altered versions must be plainly marked as such, and must not be + misrepresented as being the original software. +----------------------------------------------------------------------------- +*/ + +#include "internal.h" +#include "pcreposix.h" +#include "stdlib.h" + + + +/* Corresponding tables of PCRE error messages and POSIX error codes. */ + +static char *estring[] = { + ERR1, ERR2, ERR3, ERR4, ERR5, ERR6, ERR7, ERR8, ERR9, ERR10, + ERR11, ERR12, ERR13, ERR14, ERR15, ERR16, ERR17, ERR18, ERR19, ERR20, + ERR21, ERR22, ERR23 }; + +static int eint[] = { + REG_EESCAPE, /* "\\ at end of pattern" */ + REG_EESCAPE, /* "\\c at end of pattern" */ + REG_EESCAPE, /* "unrecognized character follows \\" */ + REG_BADBR, /* "numbers out of order in {} quantifier" */ + REG_BADBR, /* "number too big in {} quantifier" */ + REG_EBRACK, /* "missing terminating ] for character class" */ + REG_ECTYPE, /* "invalid escape sequence in character class" */ + REG_ERANGE, /* "range out of order in character class" */ + REG_BADRPT, /* "nothing to repeat" */ + REG_BADRPT, /* "operand of unlimited repeat could match the empty string" */ + REG_ASSERT, /* "internal error: unexpected repeat" */ + REG_BADPAT, /* "unrecognized character after (?" */ + REG_ESIZE, /* "too many capturing parenthesized sub-patterns" */ + REG_EPAREN, /* "missing )" */ + REG_ESUBREG, /* "back reference to non-existent subpattern" */ + REG_INVARG, /* "erroffset passed as NULL" */ + REG_INVARG, /* "unknown option bit(s) set" */ + REG_EPAREN, /* "missing ) after comment" */ + REG_ESIZE, /* "too many sets of parentheses" */ + REG_ESIZE, /* "regular expression too large" */ + REG_ESPACE, /* "failed to get memory" */ + REG_EPAREN, /* "unmatched brackets" */ + REG_ASSERT /* "internal error: code overflow" */ +}; + +/* Table of texts corresponding to POSIX error codes */ + +static char *pstring[] = { + "", /* Dummy for value 0 */ + "internal error", /* REG_ASSERT */ + "invalid repeat counts in {}", /* BADBR */ + "pattern error", /* BADPAT */ + "? * + invalid", /* BADRPT */ + "unbalanced {}", /* EBRACE */ + "unbalanced []", /* EBRACK */ + "collation error - not relevant", /* ECOLLATE */ + "bad class", /* ECTYPE */ + "bad escape sequence", /* EESCAPE */ + "empty expression", /* EMPTY */ + "unbalanced ()", /* EPAREN */ + "bad range inside []", /* ERANGE */ + "expression too big", /* ESIZE */ + "failed to get memory", /* ESPACE */ + "bad back reference", /* ESUBREG */ + "bad argument", /* INVARG */ + "match failed" /* NOMATCH */ +}; + + + + +/************************************************* +* Translate PCRE text code to int * +*************************************************/ + +/* PCRE compile-time errors are given as strings defined as macros. We can just +look them up in a table to turn them into POSIX-style error codes. */ + +static int +pcre_posix_error_code(const char *s) +{ +int i; +for (i = 0; i < sizeof(estring)/sizeof(char *); i++) + if (strcmp(s, estring[i]) == 0) return eint[i]; +return REG_ASSERT; +} + + + +/************************************************* +* Translate error code to string * +*************************************************/ + +size_t +regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size) +{ +char *message, *addmessage; +int length, adlength; + +message = (errcode >= sizeof(pstring)/sizeof(char *))? + "unknown error code" : pstring[errcode]; + +length = (int)strlen(message) + 1; + +if (preg != NULL && (int)preg->re_erroffset != -1) + { + addmessage = " at offset "; + adlength = (int)strlen(addmessage) + 6; + } +else adlength = 0; + +if (errbuf_size > 0) + { + if (adlength > 0 && errbuf_size >= length + adlength) + sprintf(errbuf, "%s%s%-6d", message, addmessage, preg->re_erroffset); + else + { + strncpy(errbuf, message, errbuf_size - 1); + errbuf[errbuf_size-1] = 0; + } + } + +return length + adlength; +} + + + + +/************************************************* +* Free store held by a regex * +*************************************************/ + +void +regfree(regex_t *preg) +{ +(pcre_free)(preg->re_pcre); +} + + + + +/************************************************* +* Compile a regular expression * +*************************************************/ + +/* +Arguments: + preg points to a structure for recording the compiled expression + pattern the pattern to compile + cflags compilation flags + +Returns: 0 on success + various non-zero codes on failure +*/ + +int +regcomp(regex_t *preg, const char *pattern, int cflags) +{ +char *errorptr; +int erroffset; +int options = 0; + +if ((cflags & REG_ICASE) != 0) options |= PCRE_CASELESS; +if ((cflags & REG_NEWLINE) != 0) options |= PCRE_MULTILINE; + +preg->re_pcre = pcre_compile(pattern, options, &errorptr, &erroffset); +preg->re_erroffset = erroffset; + +if (preg->re_pcre == NULL) return pcre_posix_error_code(errorptr); + +preg->re_nsub = pcre_info(preg->re_pcre, NULL, NULL); +return 0; +} + + + + +/************************************************* +* Match a regular expression * +*************************************************/ + +int +regexec(regex_t *preg, const char *string, size_t nmatch, + regmatch_t pmatch[], int eflags) +{ +int rc; +int options = 0; + +if ((eflags & REG_NOTBOL) != 0) options |= PCRE_NOTBOL; +if ((eflags & REG_NOTEOL) != 0) options |= PCRE_NOTEOL; + +preg->re_erroffset = -1; /* Only has meaning after compile */ + +rc = pcre_exec(preg->re_pcre, NULL, string, (int)strlen(string), options, + (int *)pmatch, nmatch * 2); + +if (rc == 0) return 0; /* All pmatch were filled in */ + +if (rc > 0) + { + int i; + for (i = rc; i < nmatch; i++) pmatch[i].rm_so = pmatch[i].rm_eo = -1; + return 0; + } + +else switch(rc) + { + case PCRE_ERROR_NOMATCH: return REG_NOMATCH; + case PCRE_ERROR_BADREF: return REG_ESUBREG; + case PCRE_ERROR_NULL: return REG_INVARG; + case PCRE_ERROR_BADOPTION: return REG_INVARG; + case PCRE_ERROR_BADMAGIC: return REG_INVARG; + case PCRE_ERROR_UNKNOWN_NODE: return REG_ASSERT; + case PCRE_ERROR_NOMEMORY: return REG_ESPACE; + default: return REG_ASSERT; + } +} + +/* End of pcreposix.c */ |