usr.bin/users/users.c

   1 /*      $NetBSD: users.c,v 1.16 2012/03/20 20:34:59 matt Exp $  */
   2
   3 /*
   4  * Copyright (c) 1980, 1987, 1993
   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) 1980, 1987, 1993\
  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[] = "@(#)users.c     8.1 (Berkeley) 6/6/93";
  41 #endif
  42 __RCSID("$NetBSD: users.c,v 1.16 2012/03/20 20:34:59 matt Exp $");
  43 #endif /* not lint */
  44
  45 #include <sys/types.h>
  46
  47 #include <err.h>
  48 #include <time.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53
  54 #include "utmpentry.h"
  55
  56 int     main(int, char **);
  57
  58 int
  59 main(int argc, char **argv)
  60 {
  61         int ncnt = 0;
  62         int ch;
  63         struct utmpentry *from, *ehead, *save, **nextp;
  64
  65         while ((ch = getopt(argc, argv, "")) != -1)
  66                 switch(ch) {
  67                 case '?':
  68                 default:
  69                         (void)fprintf(stderr, "usage: %s\n", getprogname());
  70                         exit(1);
  71                 }
  72         argc -= optind;
  73         argv += optind;
  74
  75         ncnt = getutentries(NULL, &ehead);
  76
  77         if (ncnt == 0)
  78                 return 0;
  79
  80         /*
  81          * XXX the utmp list belongs to getutentries and we shouldn't
  82          * sort it in place. Since we don't call endutentries and we
  83          * don't call getutentries again it doesn't matter, but it's
  84          * untidy. Maybe give getutentries a sort function? It has to
  85          * sort anyway if it's merging utmp and utmpx data.
  86          */
  87
  88         from = ehead;
  89         ehead = NULL;
  90         while (from != NULL) {
  91                 for (nextp = &ehead;
  92                     (*nextp) && strcmp(from->name, (*nextp)->name) > 0;
  93                     nextp = &(*nextp)->next)
  94                         continue;
  95                 save = from;
  96                 from = from->next;
  97                 save->next = *nextp;
  98                 *nextp = save;
  99         }
 100
 101         save = ehead;
 102         (void)printf("%s", ehead->name);
 103
 104         for (from = ehead->next; from; from = from->next)
 105                 if (strcmp(save->name, from->name) != 0) {
 106                         (void)printf(" %s", from->name);
 107                         save = from;
 108                 }
 109
 110         (void)printf("\n");
 111         exit(0);
 112 }