xref: /netbsd-src/usr.bin/users/users.c (revision 28c37e673e4d9b6cbdc7483062b915cc61d1ccf5)
1 /*	$NetBSD: users.c,v 1.10 2002/08/01 23:51:20 christos 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1980, 1987, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)users.c	8.1 (Berkeley) 6/6/93";
45 #endif
46 __RCSID("$NetBSD: users.c,v 1.10 2002/08/01 23:51:20 christos Exp $");
47 #endif /* not lint */
48 
49 #include <sys/types.h>
50 
51 #include <err.h>
52 #include <time.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <unistd.h>
56 #include <string.h>
57 #include <unistd.h>
58 
59 #include "utmpentry.h"
60 
61 int	main __P((int, char **));
62 
63 int
64 main(argc, argv)
65 	int argc;
66 	char **argv;
67 {
68 	int ncnt = 0;
69 	int ch;
70 	struct utmpentry *from, *ehead, *save, **nextp;
71 
72 	while ((ch = getopt(argc, argv, "")) != -1)
73 		switch(ch) {
74 		case '?':
75 		default:
76 			(void)fprintf(stderr, "Usage: %s\n", getprogname());
77 			exit(1);
78 		}
79 	argc -= optind;
80 	argv += optind;
81 
82 	ncnt = getutentries(NULL, &ehead);
83 
84 	if (ncnt == 0)
85 		return 0;
86 
87 	from = ehead;
88 	ehead = NULL;
89 	while (from != NULL) {
90 		for (nextp = &ehead;
91 		    (*nextp) && strcmp(from->name, (*nextp)->name) > 0;
92 		    nextp = &(*nextp)->next)
93 			continue;
94 		save = from;
95 		from = from->next;
96 		save->next = *nextp;
97 		*nextp = save;
98 	}
99 
100 	save = ehead;
101 	(void)printf("%s", ehead->name);
102 
103 	for (from = ehead->next; from; from = from->next)
104 		if (strcmp(save->name, from->name) != 0) {
105 			(void)printf(" %s", from->name);
106 			save = from;
107 		}
108 
109 	(void)printf("\n");
110 	exit(0);
111 }
112