root/usr/src/cmd/dirname/dirname.c
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libintl.h>

int
main(int argc, char **argv)
{
        char    *p;
        char    *string;

        /*
         * For better performance, defer the setlocale()/textdomain()
         * calls until they get really required.
         */
#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
        if (argc == 1) {
                (void) puts(".");
                return (0);
        }
        if (strcmp(argv[1], "--") == 0) {
                argv++;
                argc--;
                if (argc == 1) {
                        (void) puts(".");
                        return (0);
                }
        }
        if (argc > 2) {
                (void) setlocale(LC_ALL, "");
                (void) textdomain(TEXT_DOMAIN);
                (void) fprintf(stderr, gettext("Usage: dirname [ path ]\n"));
                return (1);
        }

        string = argv[1];

        if (*string == '\0') {
                (void) puts(".");
                return (0);
        }

        /* remove trailing slashes */
        p = string + strlen(string) - 1;
        while (p >= string && *p == '/')
                *p-- = '\0';

        if (*string == '\0') {
                /* string contained only slashes */
                (void) puts("/");
                return (0);
        }

        /* remove non-slashes */
        while (p >= string && *p != '/')
                *p-- = '\0';

        if (*string == '\0') {
                /* string did not begin with a slash */
                (void) puts(".");
                return (0);
        }

        /* remove slashes delimiting dirname and basename */
        while (p >= string && *p == '/')
                *p-- = '\0';

        if (*string == '\0') {
                /* no dirname part found */
                (void) puts("/");
                return (0);
        }
        /* now string points to dirname part */
        (void) puts(string);
        return (0);
}