cmd/groups/groups.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.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

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

/*
 * groups - show group memberships
 */
/* LINTLIBRARY PROTOLIB1 */

#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

extern struct group *getgrgid();
extern struct passwd *getpwnam();
extern int _getgroupsbymember(const char *, gid_t[], int, int);

static void showgroups();

static int ngroups_max;

int
main(int argc, char *argv[])
{
    int xval = 0;
    struct passwd *pw;

    ngroups_max = sysconf(_SC_NGROUPS_MAX);

    if (ngroups_max < 0) {
        (void) fprintf(stderr,
            "groups: could not get configuration info\n");
        exit(1);
    }

    if (ngroups_max == 0)
        exit(0);

    if (argc == 1) {

        if ((pw = getpwuid(getuid())) == NULL) {
            (void) fprintf(stderr, "groups: No passwd entry\n");
            xval = 1;
        } else
            showgroups(pw);

    } else while (*++argv) {

        if ((pw = getpwnam(*argv)) == NULL) {
            (void) fprintf(stderr,
                "groups: %s : No such user\n", *argv);
            xval = 1;
        } else {
            if (argc > 2)
                (void) printf("%s : ", *argv);
            showgroups(pw);
        }
    }

    return (xval);

}

static void
showgroups(struct passwd *pw)
{
    struct group *gr;
    static gid_t *groups = NULL;
    int ngroups;
    int i;

    if (groups == NULL) {
        if ((groups = (gid_t *)calloc((uint_t)ngroups_max,
                        sizeof (gid_t))) == 0) {
            (void) fprintf(stderr,
                "allocation of %d bytes failed\n",
                ngroups_max * sizeof (gid_t));
            exit(1);
        }
    }
    groups[0] = pw->pw_gid;

    ngroups = _getgroupsbymember(pw->pw_name, groups, ngroups_max, 1);

    if (gr = getgrgid(groups[0]))
        (void) printf("%s", gr->gr_name);
    else
        (void) printf("%d", (int)pw->pw_gid);

    for (i = 1; i < ngroups; i++) {
        if ((gr = getgrgid(groups[i])))
            (void) printf(" %s", gr->gr_name);
        else
            (void) printf(" %d", (int)groups[i]);
    }

    (void) printf("\n");
}