1 /* $OpenBSD: users.c,v 1.3 1997/01/15 23:43:30 millert Exp $ */ 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. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 static char copyright[] = 39 "@(#) Copyright (c) 1980, 1987, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 #if 0 45 static char sccsid[] = "@(#)users.c 8.1 (Berkeley) 6/6/93"; 46 #endif 47 static char rcsid[] = "$OpenBSD: users.c,v 1.3 1997/01/15 23:43:30 millert Exp $"; 48 #endif /* not lint */ 49 50 #include <sys/types.h> 51 #include <utmp.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <err.h> 56 57 typedef char namebuf[UT_NAMESIZE]; 58 59 int scmp __P((const void *, const void *)); 60 61 int 62 main(argc, argv) 63 int argc; 64 char **argv; 65 { 66 namebuf *names = NULL; 67 register int ncnt = 0; 68 register int nmax = 0; 69 int cnt; 70 struct utmp utmp; 71 int ch; 72 73 while ((ch = getopt(argc, argv, "")) != -1) 74 switch(ch) { 75 case '?': 76 default: 77 (void)fprintf(stderr, "usage: users\n"); 78 exit(1); 79 } 80 argc -= optind; 81 argv += optind; 82 83 if (!freopen(_PATH_UTMP, "r", stdin)) { 84 err(1, "can't open %s", _PATH_UTMP); 85 /* NOTREACHED */ 86 } 87 88 while (fread((char *)&utmp, sizeof(utmp), 1, stdin) == 1) { 89 if (*utmp.ut_name) { 90 if (ncnt >= nmax) { 91 nmax += 32; 92 names = realloc(names, 93 sizeof (*names) * nmax); 94 95 if (!names) { 96 err(1, NULL); 97 /* NOTREACHED */ 98 } 99 } 100 101 (void)strncpy(names[ncnt], utmp.ut_name, UT_NAMESIZE); 102 ++ncnt; 103 } 104 } 105 106 if (ncnt) { 107 qsort(names, ncnt, UT_NAMESIZE, scmp); 108 (void)printf("%.*s", UT_NAMESIZE, names[0]); 109 for (cnt = 1; cnt < ncnt; ++cnt) 110 if (strncmp(names[cnt], names[cnt - 1], UT_NAMESIZE)) 111 (void)printf(" %.*s", UT_NAMESIZE, names[cnt]); 112 (void)printf("\n"); 113 } 114 exit(0); 115 } 116 117 int 118 scmp(p, q) 119 const void *p, *q; 120 { 121 return(strncmp((char *) p, (char *) q, UT_NAMESIZE)); 122 } 123