regexp.c

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/*
 * $Id$
 *
 * Regular expression functions
 *
 * Copyright (C) 2003 Juha Heinanen
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version
 *
 * Kamailio 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <sys/types.h>
#include <string.h>
#include <regex.h>
#include <ctype.h>
#include "regexp.h"
#include "../../dprint.h"

int replace(regmatch_t* pmatch, char* string, char* replacement, str* result)
{
        int len, i, j, digit, size;

        len = strlen(replacement);
        j = 0;

        for (i = 0; i < len; i++) {
                if (replacement[i] == '\\') {
                        if (i < len - 1) {
                                if (isdigit((unsigned char)replacement[i+1])) {
                                        digit = replacement[i+1] - '0';
                                        if (pmatch[digit].rm_so != -1) {
                                                size = pmatch[digit].rm_eo - pmatch[digit].rm_so;
                                                if (j + size < result->len) {
                                                        memcpy(&(result->s[j]), string+pmatch[digit].rm_so, size);
                                                        j = j + size;
                                                } else {
                                                        return -1;
                                                }
                                        } else {
                                                return -2;
                                        }
                                        i = i + 1;
                                        continue;
                                } else {
                                        i = i + 1;
                                }
                        } else {
                                return -3;
                        }
                }
                if (j + 1 < result->len) {
                        result->s[j] = replacement[i];
                        j = j + 1;
                } else {
                        return -4;
                }
        }
        result->len = j;
        return 1;
}


int reg_match(char *pattern, char *string, regmatch_t *pmatch)
{
        regex_t preg;

        if (regcomp(&preg, pattern, REG_EXTENDED | REG_NEWLINE)) {
                return -1;
        }
        if (preg.re_nsub > MAX_MATCH) {
                regfree(&preg);
                return -2;
        }
        if (regexec(&preg, string, MAX_MATCH, pmatch, 0)) {
                regfree(&preg);
                return -3;
        }
        regfree(&preg);
        return 0;
}


int reg_replace(char *pattern, char *replacement, char *string, str *result)
{
        regmatch_t pmatch[MAX_MATCH];

        LM_DBG("pattern: '%s', replacement: '%s', string: '%s'\n",
            pattern, replacement, string);

        if (reg_match(pattern, string, &(pmatch[0]))) {
                return -1;
        }

        return replace(&pmatch[0], string, replacement, result);

}