xref: /trueos/usr.bin/users/users.c (revision 2c6741be0f59191f2283eb268e4f7690399d578a)
1 /*
2  * Copyright (c) 1980, 1987, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1980, 1987, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif /* not lint */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)users.c	8.1 (Berkeley) 6/6/93";
39 #endif
40 static const char rcsid[] =
41   "$FreeBSD$";
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/types.h>
46 #include <err.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <utmpx.h>
52 
53 typedef char   namebuf[sizeof(((struct utmpx *)0)->ut_user) + 1];
54 
55 int scmp(const void *, const void *);
56 static void usage(void);
57 
58 int
main(int argc,char ** argv)59 main(int argc, char **argv)
60 {
61 	namebuf *names = NULL;
62 	int ncnt = 0;
63 	int nmax = 0;
64 	int cnt;
65 	struct utmpx *ut;
66 	int ch;
67 
68 	while ((ch = getopt(argc, argv, "")) != -1)
69 		switch(ch) {
70 		case '?':
71 		default:
72 			usage();
73 		}
74 	argc -= optind;
75 	argv += optind;
76 
77 	setutxent();
78 	while ((ut = getutxent()) != NULL) {
79 		if (ut->ut_type != USER_PROCESS)
80 			continue;
81 		if (ncnt >= nmax) {
82 			nmax += 32;
83 			names = realloc(names, sizeof(*names) * nmax);
84 			if (!names) {
85 				errx(1, "realloc");
86 				/* NOTREACHED */
87 			}
88 		}
89 		(void)strlcpy(names[ncnt], ut->ut_user, sizeof(*names));
90 		++ncnt;
91 	}
92 	endutxent();
93 	if (ncnt > 0) {
94 		qsort(names, ncnt, sizeof(namebuf), scmp);
95 		(void)printf("%s", names[0]);
96 		for (cnt = 1; cnt < ncnt; ++cnt)
97 			if (strcmp(names[cnt], names[cnt - 1]) != 0)
98 				(void)printf(" %s", names[cnt]);
99 		(void)printf("\n");
100 	}
101 	exit(0);
102 }
103 
104 static void
usage(void)105 usage(void)
106 {
107 	(void)fprintf(stderr, "usage: users\n");
108 	exit(1);
109 }
110 
111 int
scmp(const void * p,const void * q)112 scmp(const void *p, const void *q)
113 {
114 
115 	return (strcmp(p, q));
116 }
117