users.c revision 200154
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 35static 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 42static char sccsid[] = "@(#)users.c 8.1 (Berkeley) 6/6/93"; 43#endif 44static const char rcsid[] = 45 "$FreeBSD: head/usr.bin/users/users.c 200154 2009-12-05 19:54:37Z ed $"; 46#endif /* not lint */ 47 48#include <sys/param.h> 49#include <sys/types.h> 50#include <err.h> 51#include <stdio.h> 52#include <stdlib.h> 53#include <string.h> 54#define _ULOG_POSIX_NAMES 55#include <ulog.h> 56#include <unistd.h> 57 58typedef char namebuf[MAXLOGNAME]; 59 60int scmp(const void *, const void *); 61static void usage(void); 62 63int 64main(int argc, char **argv) 65{ 66 namebuf *names = NULL; 67 int ncnt = 0; 68 int nmax = 0; 69 int cnt; 70 struct utmpx *ut; 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 setutxent(); 83 while ((ut = getutxent()) != NULL) { 84 if (ut->ut_type != USER_PROCESS) 85 continue; 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)strlcpy(names[ncnt], ut->ut_user, sizeof(*names)); 95 ++ncnt; 96 } 97 endutxent(); 98 if (ncnt > 0) { 99 qsort(names, ncnt, sizeof(namebuf), scmp); 100 (void)printf("%s", names[0]); 101 for (cnt = 1; cnt < ncnt; ++cnt) 102 if (strcmp(names[cnt], names[cnt - 1]) != 0) 103 (void)printf(" %s", names[cnt]); 104 (void)printf("\n"); 105 } 106 exit(0); 107} 108 109static void 110usage(void) 111{ 112 (void)fprintf(stderr, "usage: users\n"); 113 exit(1); 114} 115 116int 117scmp(const void *p, const void *q) 118{ 119 120 return (strcmp(p, q)); 121} 122