usr/src/lib/libc/gen/fnmatch.c

/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Guido van Rossum.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)fnmatch.c   8.1 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

/*
 * Function fnmatch() as proposed in POSIX 1003.2 B.6 (D11.2).
 * Compares a filename or pathname to a pattern.
 */

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

#define EOS     '\0'

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

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

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

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

                        /* General case, use recursion. */
                        while ((test = *string) != EOS) {
                                if (!fnmatch(pattern, string, flags))
                                        return (0);
                                if (test == '/' && flags & FNM_PATHNAME)
                                        break;
                                ++string;
                        }
                        return (FNM_NOMATCH);
                case '[':
                        if ((test = *string++) == EOS ||
                            test == '/' && flags & FNM_PATHNAME)
                                return (FNM_NOMATCH);
                        if ((pattern = rangematch(pattern, test)) == NULL)
                                return (FNM_NOMATCH);
                        break;
                case '\\':
                        if (!(flags & FNM_NOESCAPE)) {
                                if ((c = *pattern++) == EOS) {
                                        c = '\\';
                                        --pattern;
                                }
                                if (c != *string++)
                                        return (FNM_NOMATCH);
                                break;
                        }
                        /* FALLTHROUGH */
                default:
                        if (c != *string++)
                                return (FNM_NOMATCH);
                        break;
                }
        /* NOTREACHED */
}

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

        if (negate = (*pattern == '!'))
                ++pattern;

        /*
         * XXX
         * TO DO: quoting
         */
        for (ok = 0; (c = *pattern++) != ']';) {
                if (c == EOS)
                        return (NULL);          /* Illegal pattern. */
                if (*pattern == '-' && (c2 = pattern[1]) != EOS && c2 != ']') {
                        if (c <= test && test <= c2)
                                ok = 1;
                        pattern += 2;
                }
                else if (c == test)
                        ok = 1;
        }
        return (ok == negate ? NULL : pattern);
}