1 /* $NetBSD: who.c,v 1.3 1994/11/14 05:13:17 jtc Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Michael Fischbein. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #ifndef lint 40 static char copyright[] = 41 "@(#) Copyright (c) 1989, 1993\n\ 42 The Regents of the University of California. All rights reserved.\n"; 43 #endif /* not lint */ 44 45 #ifndef lint 46 #if 0 47 static char sccsid[] = "@(#)who.c 8.1 (Berkeley) 6/6/93"; 48 #endif 49 static char rcsid[] = "$NetBSD: who.c,v 1.3 1994/11/14 05:13:17 jtc Exp $"; 50 #endif /* not lint */ 51 52 #include <sys/types.h> 53 #include <sys/file.h> 54 #include <sys/time.h> 55 #include <pwd.h> 56 #include <utmp.h> 57 #include <stdio.h> 58 59 main(argc, argv) 60 int argc; 61 char **argv; 62 { 63 register char *p; 64 struct utmp usr; 65 struct passwd *pw; 66 FILE *ufp, *file(); 67 char *t, *rindex(), *strcpy(), *strncpy(), *ttyname(); 68 time_t time(); 69 70 switch (argc) { 71 case 1: /* who */ 72 ufp = file(_PATH_UTMP); 73 /* only entries with both name and line fields */ 74 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 75 if (*usr.ut_name && *usr.ut_line) 76 output(&usr); 77 break; 78 case 2: /* who utmp_file */ 79 ufp = file(argv[1]); 80 /* all entries */ 81 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 82 output(&usr); 83 break; 84 case 3: /* who am i */ 85 ufp = file(_PATH_UTMP); 86 87 /* search through the utmp and find an entry for this tty */ 88 if (p = ttyname(0)) { 89 /* strip any directory component */ 90 if (t = rindex(p, '/')) 91 p = t + 1; 92 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 93 if (usr.ut_name && !strcmp(usr.ut_line, p)) { 94 output(&usr); 95 exit(0); 96 } 97 /* well, at least we know what the tty is */ 98 (void)strncpy(usr.ut_line, p, UT_LINESIZE); 99 } else 100 (void)strcpy(usr.ut_line, "tty??"); 101 pw = getpwuid(getuid()); 102 (void)strncpy(usr.ut_name, pw ? pw->pw_name : "?", UT_NAMESIZE); 103 (void)time(&usr.ut_time); 104 *usr.ut_host = '\0'; 105 output(&usr); 106 break; 107 default: 108 (void)fprintf(stderr, "usage: who [ file ]\n who am i\n"); 109 exit(1); 110 } 111 exit(0); 112 } 113 114 output(up) 115 struct utmp *up; 116 { 117 char *ctime(); 118 119 (void)printf("%-*.*s %-*.*s", UT_NAMESIZE, UT_NAMESIZE, up->ut_name, 120 UT_LINESIZE, UT_LINESIZE, up->ut_line); 121 (void)printf("%.12s", ctime(&up->ut_time) + 4); 122 if (*up->ut_host) 123 printf("\t(%.*s)", UT_HOSTSIZE, up->ut_host); 124 (void)putchar('\n'); 125 } 126 127 FILE * 128 file(name) 129 char *name; 130 { 131 extern int errno; 132 FILE *ufp; 133 char *strerror(); 134 135 if (!(ufp = fopen(name, "r"))) { 136 (void)fprintf(stderr, "who: %s: %s.\n", name, strerror(errno)); 137 exit(1); 138 } 139 return(ufp); 140 } 141