libc/gen/base.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 (c) 1996, by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * MKS Library -- basename -- produce base name of a file name
 * NOTE: not standard SVID routine.
 *
 * Copyright 1985, 1995 by Mortice Kern Systems Inc.  All rights reserved.
 *
 * james Partanen, June '95
 *
 */
#ifdef M_RCSID
#ifndef lint
static char rcsID[] = "$Header: /rd/src/libc/gen/rcs/base.c 1.26 1995/08/02 17:32:36 rodney Exp $";
#endif
#endif

#include <string.h>

#define DIRNAME     0
#define BASENAME    1

#define M_FSDELIM(c)    ((c)=='/')
#define M_DRDELIM(c)    (0)

static char curdir[] = ".";

/*f
 * Since the goal is essentially common: find the last occurring
 * M_FSDELIM, and since most of the degenerate cases end up with the
 * same result, let's do most of the work in one function.
 *  - check degenerate arg forms
 *  - deal with a possible drive specifier
 *  - deal with degenerate paths
 *  - find last non-trailing M_FSDELIM
 *  - deal with degenerate dirname
 *  - deal with general case, returning prefix or suffix based on type
 */
static char *
basedir(char *arg, int type)
{
    register char *cp, *path;

    if (arg==(char *)0 || *arg=='\0' ||
        (*arg=='.' && (arg[1]=='\0' ||
        (type==DIRNAME && arg[1]=='.' && arg[2]=='\0'))))

        return curdir;  /* arg NULL, empty, ".", or ".." in DIRNAME */

    if (M_DRDELIM(arg[1]))  /* drive-specified pathnames */
        path = arg+2;
    else
        path = arg;

    if (path[1]=='\0'&&M_FSDELIM(*path))    /* "/", or drive analog */
        return arg;

    cp = strchr(path, '\0');
    cp--;

    while (cp != path && M_FSDELIM(*cp))
        *(cp--) = '\0';

    for (;cp>path && !M_FSDELIM(*cp); cp--)
        ;

    if (!M_FSDELIM(*cp))
        if (type==DIRNAME && path!=arg) {
            *path = '\0';
            return arg; /* curdir on the specified drive */
        } else
            return (type==DIRNAME)?curdir:path;
    else if (cp == path && type == DIRNAME) {
        cp[1] = '\0';
        return arg;     /* root directory involved */
    } else if (cp == path && cp[1] == '\0')
        return(arg);
    else if (type == BASENAME)
        return ++cp;
    *cp = '\0';
    return arg;
}

/*f
 * Finds the dirname of the given file.  Spec1170 conformant.
 */
char *
dirname(char *arg)
{
    return(basedir(arg, DIRNAME));
}

/*f
 * Finds the basename of the given file.  Spec1170 conformant.
 */
char *
basename(char *arg)
{
    return(basedir(arg, BASENAME));
}

#ifdef TEST_MAIN_BASE_C
#include <stdio.h>

int main(int argc, char **argv)
{
    int cnt;
    char arg[128];
    char *tmp;

    if (argc>1) {
        for (cnt=argc--;argc;argc--) {
            tmp = strdup(argv[cnt-argc]);
            printf("%s\t%s\n",
                dirname(argv[cnt-argc]),
                basename(tmp));
            free(tmp);
        }
        return 0;
    }

    printf("enter pathnames less than 128 chars.  enter 'q' to quit.\n");

    while(gets(arg))
        if (!strcmp(arg, "q"))
            break;
        else {
            tmp = strdup(arg);
            printf("%s\t%s\n", dirname(arg), basename(tmp));
            free(tmp);
        }

    return 0;
}
#endif /* TEST_MAIN_BASE_C */