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 <time.h> 50 #include <pwd.h> 51 #include <utmp.h> 52 #include <stdio.h> 53 #include <locale.h> 54 55 main(argc, argv) 56 int argc; 57 char **argv; 58 { 59 register char *p; 60 struct utmp usr; 61 struct passwd *pw; 62 FILE *ufp, *file(); 63 char *t, *rindex(), *strcpy(), *strncpy(), *ttyname(); 64 65 (void) setlocale(LC_TIME, ""); 66 67 switch (argc) { 68 case 1: /* who */ 69 ufp = file(_PATH_UTMP); 70 /* only entries with both name and line fields */ 71 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 72 if (*usr.ut_name && *usr.ut_line) 73 output(&usr); 74 break; 75 case 2: /* who utmp_file */ 76 ufp = file(argv[1]); 77 /* all entries */ 78 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 79 output(&usr); 80 break; 81 case 3: /* who am i */ 82 ufp = file(_PATH_UTMP); 83 84 /* search through the utmp and find an entry for this tty */ 85 if (p = ttyname(0)) { 86 /* strip any directory component */ 87 if (t = rindex(p, '/')) 88 p = t + 1; 89 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 90 if (usr.ut_name && !strcmp(usr.ut_line, p)) { 91 output(&usr); 92 exit(0); 93 } 94 /* well, at least we know what the tty is */ 95 (void)strncpy(usr.ut_line, p, UT_LINESIZE); 96 } else 97 (void)strcpy(usr.ut_line, "tty??"); 98 pw = getpwuid(getuid()); 99 (void)strncpy(usr.ut_name, pw ? pw->pw_name : "?", UT_NAMESIZE); 100 (void)time(&usr.ut_time); 101 *usr.ut_host = '\0'; 102 output(&usr); 103 break; 104 default: 105 (void)fprintf(stderr, "usage: who [ file ]\n who am i\n"); 106 exit(1); 107 } 108 exit(0); 109 } 110 111 output(up) 112 struct utmp *up; 113 { 114 char buf[80]; 115 116 (void)printf("%-*.*s %-*.*s", UT_NAMESIZE, UT_NAMESIZE, up->ut_name, 117 UT_LINESIZE, UT_LINESIZE, up->ut_line); 118 (void)strftime(buf, sizeof(buf), "%c", localtime(&up->ut_time)); 119 (void)printf("%.12s", buf + 4); 120 if (*up->ut_host) 121 printf("\t(%.*s)", UT_HOSTSIZE, up->ut_host); 122 (void)putchar('\n'); 123 } 124 125 FILE * 126 file(name) 127 char *name; 128 { 129 extern int errno; 130 FILE *ufp; 131 char *strerror(); 132 133 if (!(ufp = fopen(name, "r"))) { 134 (void)fprintf(stderr, "who: %s: %s.\n", name, strerror(errno)); 135 exit(1); 136 } 137 return(ufp); 138 } 139