1 /* 2 * Copyright (c) 1980, 1987 Regents of the University of California. 3 * 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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 char copyright[] = 36 "@(#) Copyright (c) 1980, 1987 Regents of the University of California.\n\ 37 All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 /*static char sccsid[] = "from: @(#)users.c 5.12 (Berkeley) 11/1/90";*/ 42 static char rcsid[] = "$Id: users.c,v 1.2 1993/08/01 18:03:46 mycroft Exp $"; 43 #endif /* not lint */ 44 45 #include <sys/types.h> 46 #include <utmp.h> 47 #include <stdio.h> 48 49 #define MAXUSERS 200 50 51 main(argc, argv) 52 int argc; 53 char **argv; 54 { 55 extern int optind; 56 register int cnt, ncnt; 57 struct utmp utmp; 58 char names[MAXUSERS][UT_NAMESIZE]; 59 int ch, scmp(); 60 61 while ((ch = getopt(argc, argv, "")) != EOF) 62 switch(ch) { 63 case '?': 64 default: 65 (void)fprintf(stderr, "usage: users\n"); 66 exit(1); 67 } 68 argc -= optind; 69 argv += optind; 70 71 if (!freopen(_PATH_UTMP, "r", stdin)) { 72 (void)fprintf(stderr, "users: can't open %s.\n", _PATH_UTMP); 73 exit(1); 74 } 75 for (ncnt = 0; 76 fread((char *)&utmp, sizeof(utmp), 1, stdin) == 1;) 77 if (*utmp.ut_name) { 78 if (ncnt == MAXUSERS) { 79 (void)fprintf(stderr, 80 "users: too many users.\n"); 81 break; 82 } 83 (void)strncpy(names[ncnt], utmp.ut_name, UT_NAMESIZE); 84 ++ncnt; 85 } 86 87 if (ncnt) { 88 qsort(names, ncnt, UT_NAMESIZE, scmp); 89 (void)printf("%.*s", UT_NAMESIZE, names[0]); 90 for (cnt = 1; cnt < ncnt; ++cnt) 91 if (strncmp(names[cnt], names[cnt - 1], UT_NAMESIZE)) 92 (void)printf(" %.*s", UT_NAMESIZE, names[cnt]); 93 (void)printf("\n"); 94 } 95 exit(0); 96 } 97 98 scmp(p, q) 99 char *p, *q; 100 { 101 return(strncmp(p, q, UT_NAMESIZE)); 102 } 103