lib/lp/getname.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) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"
/*
 *  getname(name)  --  get logname
 *
 *      getname tries to find the user's logname from:
 *          ${LOGNAME}, if set and if it is telling the truth
 *          /etc/passwd, otherwise
 *
 *      The logname is returned as the value of the function.
 *
 *      Getname returns the user's user id converted to ASCII
 *      for unknown lognames.
 *
 */

#include "string.h"
#include "pwd.h"
#include "errno.h"
#include "sys/types.h"
#include "stdlib.h"
#include "unistd.h"

#include "lp.h"

char *
#if defined(__STDC__)
getname (
    void
)
#else
getname ()
#endif
{
    uid_t           uid;
    struct passwd       *p;
    static char     *logname    = 0;
    char            *l;

    if (logname)
        return (logname);

    uid = getuid();

    setpwent ();
    if (
        !(l = getenv("LOGNAME"))
         || !(p = getpwnam(l))
         || p->pw_uid != uid
    )
        if ((p = getpwuid(uid)))
            l = p->pw_name;
        else
            l = 0;
    endpwent ();

    if (l)
        logname = Strdup(l);
    else {
        if (uid > 0) {
            logname = Malloc(10 + 1);
            if (logname)
                sprintf (logname, "%d", uid);
        }
    }

    if (!logname)
    {
        errno = ENOMEM;
    }
    else
    {
        errno = 0;
    }

    return (logname);
}