users.c revision 296373
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 31static 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 38static char sccsid[] = "@(#)users.c 8.1 (Berkeley) 6/6/93"; 39#endif 40static const char rcsid[] = 41 "$FreeBSD: releng/10.3/usr.bin/users/users.c 223222 2011-06-18 07:47:15Z ed $"; 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 53typedef char namebuf[sizeof(((struct utmpx *)0)->ut_user) + 1]; 54 55int scmp(const void *, const void *); 56static void usage(void); 57 58int 59main(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 104static void 105usage(void) 106{ 107 (void)fprintf(stderr, "usage: users\n"); 108 exit(1); 109} 110 111int 112scmp(const void *p, const void *q) 113{ 114 115 return (strcmp(p, q)); 116} 117