Annotation of src/usr.bin/users/users.c, Revision 1.8
1.8 ! tedu 1: /* $OpenBSD: users.c,v 1.7 2003/06/03 02:56:21 millert Exp $ */
1.1 deraadt 2: /* $NetBSD: users.c,v 1.5 1994/12/20 15:58:19 jtc Exp $ */
3:
4: /*
5: * Copyright (c) 1980, 1987, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
1.7 millert 16: * 3. Neither the name of the University nor the names of its contributors
1.1 deraadt 17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: */
32:
33: #ifndef lint
34: static char copyright[] =
35: "@(#) Copyright (c) 1980, 1987, 1993\n\
36: The Regents of the University of California. All rights reserved.\n";
37: #endif /* not lint */
38:
39: #ifndef lint
40: #if 0
41: static char sccsid[] = "@(#)users.c 8.1 (Berkeley) 6/6/93";
42: #endif
1.8 ! tedu 43: static char rcsid[] = "$OpenBSD: users.c,v 1.7 2003/06/03 02:56:21 millert Exp $";
1.1 deraadt 44: #endif /* not lint */
45:
46: #include <sys/types.h>
47: #include <utmp.h>
48: #include <stdio.h>
49: #include <stdlib.h>
50: #include <string.h>
51: #include <err.h>
52:
53: typedef char namebuf[UT_NAMESIZE];
54:
1.5 millert 55: int scmp(const void *, const void *);
1.1 deraadt 56:
57: int
1.6 deraadt 58: main(int argc, char *argv[])
1.1 deraadt 59: {
60: namebuf *names = NULL;
1.4 mpech 61: int ncnt = 0;
62: int nmax = 0;
1.1 deraadt 63: int cnt;
64: struct utmp utmp;
65: int ch;
66:
1.3 millert 67: while ((ch = getopt(argc, argv, "")) != -1)
1.1 deraadt 68: switch(ch) {
69: case '?':
70: default:
71: (void)fprintf(stderr, "usage: users\n");
72: exit(1);
73: }
74: argc -= optind;
75: argv += optind;
76:
77: if (!freopen(_PATH_UTMP, "r", stdin)) {
78: err(1, "can't open %s", _PATH_UTMP);
79: /* NOTREACHED */
80: }
81:
82: while (fread((char *)&utmp, sizeof(utmp), 1, stdin) == 1) {
83: if (*utmp.ut_name) {
84: if (ncnt >= nmax) {
1.8 ! tedu 85: size_t newmax = nmax + 32;
! 86: namebuf *newnames;
1.1 deraadt 87:
1.8 ! tedu 88: newnames = realloc(names,
! 89: sizeof(*names) * newmax);
! 90:
! 91: if (newnames == NULL) {
1.1 deraadt 92: err(1, NULL);
93: /* NOTREACHED */
94: }
1.8 ! tedu 95: names = newnames;
! 96: nmax = newmax;
1.1 deraadt 97: }
98:
99: (void)strncpy(names[ncnt], utmp.ut_name, UT_NAMESIZE);
100: ++ncnt;
101: }
102: }
103:
104: if (ncnt) {
105: qsort(names, ncnt, UT_NAMESIZE, scmp);
106: (void)printf("%.*s", UT_NAMESIZE, names[0]);
107: for (cnt = 1; cnt < ncnt; ++cnt)
108: if (strncmp(names[cnt], names[cnt - 1], UT_NAMESIZE))
109: (void)printf(" %.*s", UT_NAMESIZE, names[cnt]);
110: (void)printf("\n");
111: }
112: exit(0);
113: }
114:
115: int
1.6 deraadt 116: scmp(const void *p, const void *q)
1.1 deraadt 117: {
118: return(strncmp((char *) p, (char *) q, UT_NAMESIZE));
119: }