/* $NetBSD: regex.c,v 1.1.1.2 2013/04/06 14:05:44 christos Exp $ */ /** regex - regular expression functions related to POSIX regex lib. */ /* This file is part of flex. */ /* Redistribution and use in source and binary forms, with or without */ /* modification, are permitted provided that the following conditions */ /* are met: */ /* 1. Redistributions of source code must retain the above copyright */ /* notice, this list of conditions and the following disclaimer. */ /* 2. Redistributions in binary form must reproduce the above copyright */ /* notice, this list of conditions and the following disclaimer in the */ /* documentation and/or other materials provided with the distribution. */ /* Neither the name of the University nor the names of its contributors */ /* may be used to endorse or promote products derived from this software */ /* without specific prior written permission. */ /* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR */ /* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED */ /* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR */ /* PURPOSE. */ #include "flexdef.h" static const char* REGEXP_LINEDIR = "^#line ([[:digit:]]+) \"(.*)\""; static const char* REGEXP_BLANK_LINE = "^[[:space:]]*$"; regex_t regex_linedir; /**< matches line directives */ regex_t regex_blank_line; /**< matches blank lines */ /** Initialize the regular expressions. * @return true upon success. */ bool flex_init_regex(void) { flex_regcomp(®ex_linedir, REGEXP_LINEDIR, REG_EXTENDED); flex_regcomp(®ex_blank_line, REGEXP_BLANK_LINE, REG_EXTENDED); return true; } /** Compiles a regular expression or dies trying. * @param preg Same as for regcomp(). * @param regex Same as for regcomp(). * @param cflags Same as for regcomp(). */ void flex_regcomp(regex_t *preg, const char *regex, int cflags) { int err; memset (preg, 0, sizeof (regex_t)); if ((err = regcomp (preg, regex, cflags)) != 0) { const int errbuf_sz = 200; char *errbuf, *rxerr; errbuf = (char*)flex_alloc(errbuf_sz *sizeof(char)); if (!errbuf) flexfatal(_("Unable to allocate buffer to report regcomp")); rxerr = (char*)flex_alloc(errbuf_sz *sizeof(char)); if (!rxerr) flexfatal(_("Unable to allocate buffer for regerror")); regerror (err, preg, rxerr, errbuf_sz); snprintf (errbuf, errbuf_sz, "regcomp for \"%s\" failed: %s", regex, rxerr); flexfatal (errbuf); free(errbuf); free(rxerr); } } /** Extract a copy of the match, or NULL if no match. * @param m A match as returned by regexec(). * @param src The source string that was passed to regexec(). * @return The allocated string. */ char *regmatch_dup (regmatch_t * m, const char *src) { char *str; int len; if (m == NULL || m->rm_so < 0) return NULL; len = m->rm_eo - m->rm_so; str = (char *) flex_alloc ((len + 1) * sizeof (char)); if (!str) flexfatal(_("Unable to allocate a copy of the match")); strncpy (str, src + m->rm_so, len); str[len] = 0; return str; } /** Copy the match. * @param m A match as returned by regexec(). * @param dest The destination buffer. * @param src The source string that was passed to regexec(). * @return dest */ char *regmatch_cpy (regmatch_t * m, char *dest, const char *src) { if (m == NULL || m->rm_so < 0) { if (dest) dest[0] = '\0'; return dest; } snprintf (dest, regmatch_len(m), "%s", src + m->rm_so); return dest; } /** Get the length in characters of the match. * @param m A match as returned by regexec(). * @param src The source string that was passed to regexec(). * @return The length of the match. */ int regmatch_len (regmatch_t * m) { if (m == NULL || m->rm_so < 0) { return 0; } return m->rm_eo - m->rm_so; } /** Convert a regmatch_t object to an integer using the strtol() function. * @param m A match as returned by regexec(). * @param src The source string that was passed to regexec(). * @param endptr Same as the second argument to strtol(). * @param base Same as the third argument to strtol(). * @return The converted integer or error (Return value is the same as for strtol()). */ int regmatch_strtol (regmatch_t * m, const char *src, char **endptr, int base) { int n = 0; #define bufsz 20 char buf[bufsz]; char *s; if (m == NULL || m->rm_so < 0) return 0; if (regmatch_len (m) < bufsz) s = regmatch_cpy (m, buf, src); else s = regmatch_dup (m, src); n = strtol (s, endptr, base); if (s != buf) free (s); return n; } /** Check for empty or non-existent match. * @param m A match as returned by regexec(). * @return false if match length is non-zero. * Note that reg_empty returns true even if match did not occur at all. */ bool regmatch_empty (regmatch_t * m) { return (m == NULL || m->rm_so < 0 || m->rm_so == m->rm_eo); } /* vim:set expandtab cindent tabstop=4 softtabstop=4 shiftwidth=4 textwidth=0: */