usr.bin/logname/logname.c

   1 /*      $NetBSD: logname.c,v 1.10 2011/09/04 20:29:12 joerg Exp $       */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1991, 1993, 1994\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)logname.c   8.2 (Berkeley) 4/3/94";
  41 #endif
  42 __RCSID("$NetBSD: logname.c,v 1.10 2011/09/04 20:29:12 joerg Exp $");
  43 #endif /* not lint */
  44
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <locale.h>
  48 #include <unistd.h>
  49 #include <err.h>
  50
  51 __dead  static void     usage(void);
  52
  53 int
  54 main(int argc, char *argv[])
  55 {
  56         int ch;
  57         char *p;
  58
  59         setlocale(LC_ALL, "");
  60
  61         while ((ch = getopt(argc, argv, "")) != -1)
  62                 switch (ch) {
  63                 case '?':
  64                 default:
  65                         usage();
  66                         /* NOTREACHED */
  67                 }
  68
  69         if (argc != optind) {
  70                 usage();
  71                 /* NOTREACHED */
  72         }
  73
  74         if ((p = getlogin()) == NULL)
  75                 err(1, "getlogin");
  76         (void)printf("%s\n", p);
  77         exit(0);
  78 }
  79
  80 static void
  81 usage(void)
  82 {
  83         (void)fprintf(stderr, "usage: logname\n");
  84         exit(1);
  85 }