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 * 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 static const char copyright[] = 36 "@(#) Copyright (c) 1980, 1987, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)users.c 8.1 (Berkeley) 6/6/93"; 43 #endif 44 static const char rcsid[] = 45 "$FreeBSD: src/usr.bin/users/users.c,v 1.5 1999/08/28 01:07:14 peter Exp $"; 46 #endif /* not lint */ 47 48 #include <sys/types.h> 49 #include <err.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 #include <utmp.h> 55 56 typedef char namebuf[UT_NAMESIZE]; 57 58 int scmp __P((const void *, const void *)); 59 static void usage __P((void)); 60 61 int 62 main(argc, argv) 63 int argc; 64 char **argv; 65 { 66 namebuf *names = NULL; 67 int ncnt = 0; 68 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 usage(); 78 } 79 argc -= optind; 80 argv += optind; 81 82 if (!freopen(_PATH_UTMP, "r", stdin)) 83 errx(1, "can't open %s", _PATH_UTMP); 84 while (fread((char *)&utmp, sizeof(utmp), 1, stdin) == 1) { 85 if (*utmp.ut_name) { 86 if (ncnt >= nmax) { 87 nmax += 32; 88 names = realloc(names, sizeof (*names) * nmax); 89 if (!names) { 90 errx(1, "realloc"); 91 /* NOTREACHED */ 92 } 93 } 94 (void)strncpy(names[ncnt], utmp.ut_name, UT_NAMESIZE); 95 ++ncnt; 96 } 97 } 98 if (ncnt) { 99 qsort(names, ncnt, UT_NAMESIZE, scmp); 100 (void)printf("%.*s", UT_NAMESIZE, names[0]); 101 for (cnt = 1; cnt < ncnt; ++cnt) 102 if (strncmp(names[cnt], names[cnt - 1], UT_NAMESIZE)) 103 (void)printf(" %.*s", UT_NAMESIZE, names[cnt]); 104 (void)printf("\n"); 105 } 106 exit(0); 107 } 108 109 static void 110 usage() 111 { 112 (void)fprintf(stderr, "usage: users\n"); 113 exit(1); 114 } 115 116 int 117 scmp(p, q) 118 const void *p, *q; 119 { 120 return(strncmp((char *)p, (char *)q, UT_NAMESIZE)); 121 } 122