fnmatch.c

/*      $NetBSD: fnmatch.c,v 1.20 2003/08/07 16:42:48 agc 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 <u/missing/fnmatch.h>

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

#define EOS     '\0'

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

static inline int foldcase(int ch, int flags)
{

        if ((flags & FNM_CASEFOLD) != 0 && isupper(ch))
                return (tolower(ch));
        return (ch);
}

#define FOLDCASE(ch, flags)     foldcase((unsigned char)(ch), (flags))

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

        for (stringstart = string;;)
                switch (c = FOLDCASE(*pattern++, flags)) {
                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 = FOLDCASE(*pattern, flags);
                        /* Collapse multiple stars. */
                        while (c == '*')
                                c = FOLDCASE(*++pattern, flags);

                        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 = FOLDCASE(*string, flags)) != 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 ((pattern =
                            rangematch(pattern, FOLDCASE(*string, flags),
                                       flags)) == NULL)
                                return (FNM_NOMATCH);
                        ++string;
                        break;
                case '\\':
                        if (!(flags & FNM_NOESCAPE)) {
                                if ((c = FOLDCASE(*pattern++, flags)) == EOS) {
                                        c = '\\';
                                        --pattern;
                                }
                        }
                        /* FALLTHROUGH */
                default:
                        if (c != FOLDCASE(*string++, flags))
                                return (FNM_NOMATCH);
                        break;
                }
        /* NOTREACHED */
}

static const char *rangematch (const char *pattern, int test, int flags)
{
        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 == '^')) != 0)
                ++pattern;
        
        for (ok = 0; (c = FOLDCASE(*pattern++, flags)) != ']';) {
                if (c == '\\' && !(flags & FNM_NOESCAPE))
                        c = FOLDCASE(*pattern++, flags);
                if (c == EOS)
                        return (NULL);
                if (*pattern == '-' 
                    && (c2 = FOLDCASE(*(pattern+1), flags)) != EOS &&
                        c2 != ']') {
                        pattern += 2;
                        if (c2 == '\\' && !(flags & FNM_NOESCAPE))
                                c2 = FOLDCASE(*pattern++, flags);
                        if (c2 == EOS)
                                return (NULL);
                        if (c <= test && test <= c2)
                                ok = 1;
                } else if (c == test)
                        ok = 1;
        }
        return (ok == negate ? NULL : pattern);
}