/*
 * 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) 1988 AT&T */
/*        All Rights Reserved   */


/*
 * Copyright (c) 1999 by Sun Microsystems, Inc.
 * All rights reserved.
 */

/*
 *      logdir()
 *
 *      This routine does not use the getpwent(3) library routine
 *      because the latter uses the stdio package.  The allocation of
 *      storage in this package destroys the integrity of the shell's
 *      storage allocation.
 */

#include <fcntl.h>      /* O_RDONLY */
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

#define BUFSIZ  160

static char line[BUFSIZ+1];

static char *
passwdfield(char *p)
{
        while (*p && *p != ':')
                ++p;
        if (*p)
                *p++ = 0;
        return (p);
}

char *
logdir(char *name)
{
        char    *p;
        int     i, j;
        int     pwf;

        /* attempt to open the password file */
        if ((pwf = open("/etc/passwd", O_RDONLY)) == -1)
                return (0);

        /* find the matching password entry */
        do {
                /* get the next line in the password file */
                i = read(pwf, line, BUFSIZ);
                for (j = 0; j < i; j++)
                        if (line[j] == '\n')
                                break;
                /* return a null pointer if the whole file has been read */
                if (j >= i)
                        return (0);
                line[++j] = 0;                  /* terminate the line */
                /* point at the next line */
                (void) lseek(pwf, (long)(j - i), 1);
                p = passwdfield(line);          /* get the logname */
        } while (*name != *line ||      /* fast pretest */
            strcmp(name, line) != 0);
        (void) close(pwf);

        /* skip the intervening fields */
        p = passwdfield(p);
        p = passwdfield(p);
        p = passwdfield(p);
        p = passwdfield(p);

        /* return the login directory */
        (void) passwdfield(p);
        return (p);
}