/*      $OpenBSD: fnmatch.c,v 1.13 2006/03/31 05:34:14 deraadt Exp $        */

/*
 * Copyright (c) 1989, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Guido van Rossum.
 *
 * 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.
 * 3. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Function fnmatch() as specified in POSIX 1003.2-1992, section B.6.
 * Compares a filename or pathname to a pattern.
 */

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <fnmatch.h>

#define EOS        '\0'

#define RANGE_MATCH        1
#define RANGE_NOMATCH        0
#define RANGE_ERROR        (-1)

static int rangematch(const char *, char, int, char **);

int
fnmatch(const char *pattern, const char *string, int flags)
{
        const char *stringstart;
        char *newp;
        char c, test;

        for (stringstart = string;;)
                switch (c = *pattern++) {
                case EOS:
                        if ((flags & FNM_LEADING_DIR) && *string == '/')
                                return (0);
                        return (*string == EOS ? 0 : FNM_NOMATCH);
                case '?':
                        if (*string == EOS)
                                return (FNM_NOMATCH);
                        if (*string == '/' && (flags & FNM_PATHNAME))
                                return (FNM_NOMATCH);
                        if (*string == '.' && (flags & FNM_PERIOD) &&
                            (string == stringstart ||
                            ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
                                return (FNM_NOMATCH);
                        ++string;
                        break;
                case '*':
                        c = *pattern;
                        /* Collapse multiple stars. */
                        while (c == '*')
                                c = *++pattern;

                        if (*string == '.' && (flags & FNM_PERIOD) &&
                            (string == stringstart ||
                            ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
                                return (FNM_NOMATCH);

                        /* Optimize for pattern with * at end or before /. */
                        if (c == EOS) {
                                if (flags & FNM_PATHNAME)
                                        return ((flags & FNM_LEADING_DIR) ||
                                            strchr(string, '/') == NULL ?
                                            0 : FNM_NOMATCH);
                                else
                                        return (0);
                        } else if (c == '/' && (flags & FNM_PATHNAME)) {
                                if ((string = strchr(string, '/')) == NULL)
                                        return (FNM_NOMATCH);
                                break;
                        }

                        /* General case, use recursion. */
                        while ((test = *string) != EOS) {
                                if (!fnmatch(pattern, string, flags & ~FNM_PERIOD))
                                        return (0);
                                if (test == '/' && (flags & FNM_PATHNAME))
                                        break;
                                ++string;
                        }
                        return (FNM_NOMATCH);
                case '[':
                        if (*string == EOS)
                                return (FNM_NOMATCH);
                        if (*string == '/' && (flags & FNM_PATHNAME))
                                return (FNM_NOMATCH);
                        if (*string == '.' && (flags & FNM_PERIOD) &&
                            (string == stringstart ||
                            ((flags & FNM_PATHNAME) && *(string - 1) == '/')))
                                return (FNM_NOMATCH);

                        switch (rangematch(pattern, *string, flags, &newp)) {
                        case RANGE_ERROR:
                                /* not a good range, treat as normal text */
                                goto normal;
                        case RANGE_MATCH:
                                pattern = newp;
                                break;
                        case RANGE_NOMATCH:
                                return (FNM_NOMATCH);
                        }
                        ++string;
                        break;
                case '\\':
                        if (!(flags & FNM_NOESCAPE)) {
                                if ((c = *pattern++) == EOS) {
                                        c = '\\';
                                        --pattern;
                                }
                        }
                        /* FALLTHROUGH */
                default:
                normal:
                        if (c != *string && !((flags & FNM_CASEFOLD) &&
                                 (tolower((unsigned char)c) ==
                                 tolower((unsigned char)*string))))
                                return (FNM_NOMATCH);
                        ++string;
                        break;
                }
        /* NOTREACHED */
}

static int
rangematch(const char *pattern, char test, int flags, char **newp)
{
        int negate, ok;
        char c, c2;

        /*
         * A bracket expression starting with an unquoted circumflex
         * character produces unspecified results (IEEE 1003.2-1992,
         * 3.13.2).  This implementation treats it like '!', for
         * consistency with the regular expression syntax.
         * J.T. Conklin (conklin@ngai.kaleida.com)
         */
        if ((negate = (*pattern == '!' || *pattern == '^')))
                ++pattern;

        if (flags & FNM_CASEFOLD)
                test = (char)tolower((unsigned char)test);

        /*
         * A right bracket shall lose its special meaning and represent
         * itself in a bracket expression if it occurs first in the list.
         * -- POSIX.2 2.8.3.2
         */
        ok = 0;
        c = *pattern++;
        do {
                if (c == '\\' && !(flags & FNM_NOESCAPE))
                        c = *pattern++;
                if (c == EOS)
                        return (RANGE_ERROR);
                if (c == '/' && (flags & FNM_PATHNAME))
                        return (RANGE_NOMATCH);
                if ((flags & FNM_CASEFOLD))
                        c = (char)tolower((unsigned char)c);
                if (*pattern == '-'
                    && (c2 = *(pattern+1)) != EOS && c2 != ']') {
                        pattern += 2;
                        if (c2 == '\\' && !(flags & FNM_NOESCAPE))
                                c2 = *pattern++;
                        if (c2 == EOS)
                                return (RANGE_ERROR);
                        if (flags & FNM_CASEFOLD)
                                c2 = (char)tolower((unsigned char)c2);
                        if (c <= test && test <= c2)
                                ok = 1;
                } else if (c == test)
                        ok = 1;
        } while ((c = *pattern++) != ']');

        *newp = (char *)pattern;
        return (ok == negate ? RANGE_NOMATCH : RANGE_MATCH);
}