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