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 const 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 #if 0 45 static char sccsid[] = "@(#)who.c 8.1 (Berkeley) 6/6/93"; 46 #endif 47 static const char rcsid[] = 48 "$FreeBSD$"; 49 #endif /* not lint */ 50 51 #include <sys/types.h> 52 #include <sys/file.h> 53 #include <err.h> 54 #include <locale.h> 55 #include <pwd.h> 56 #include <stdio.h> 57 #include <string.h> 58 #include <time.h> 59 #include <unistd.h> 60 #include <utmp.h> 61 62 static void usage __P((void)); 63 void output __P((struct utmp *)); 64 65 int 66 main(argc, argv) 67 int argc; 68 char **argv; 69 { 70 register char *p; 71 struct utmp usr; 72 struct passwd *pw; 73 FILE *ufp, *file(); 74 char *t; 75 76 (void) setlocale(LC_TIME, ""); 77 78 switch (argc) { 79 case 1: /* who */ 80 ufp = file(_PATH_UTMP); 81 /* only entries with both name and line fields */ 82 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 83 if (*usr.ut_name && *usr.ut_line) 84 output(&usr); 85 break; 86 case 2: /* who utmp_file */ 87 ufp = file(argv[1]); 88 /* all entries */ 89 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 90 output(&usr); 91 break; 92 case 3: /* who am i */ 93 if (strcmp(argv[1], "am") 94 || (strcmp(argv[2], "I") && strcmp(argv[2], "i"))) 95 usage(); 96 97 ufp = file(_PATH_UTMP); 98 99 /* search through the utmp and find an entry for this tty */ 100 if ((p = ttyname(0))) { 101 /* strip any directory component */ 102 if ((t = rindex(p, '/'))) 103 p = t + 1; 104 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 105 if (*usr.ut_name && !strcmp(usr.ut_line, p)) { 106 output(&usr); 107 exit(0); 108 } 109 /* well, at least we know what the tty is */ 110 (void)strncpy(usr.ut_line, p, UT_LINESIZE); 111 } else 112 (void)strcpy(usr.ut_line, "tty??"); 113 pw = getpwuid(getuid()); 114 (void)strncpy(usr.ut_name, pw ? pw->pw_name : "?", UT_NAMESIZE); 115 (void)time(&usr.ut_time); 116 *usr.ut_host = '\0'; 117 output(&usr); 118 break; 119 default: 120 usage(); 121 } 122 exit(0); 123 } 124 125 static void 126 usage() 127 { 128 (void)fprintf(stderr, "%s\n%s\n", 129 "usage: who [file]", 130 " who am i"); 131 exit(1); 132 } 133 134 void 135 output(up) 136 struct utmp *up; 137 { 138 char buf[80]; 139 140 (void)printf("%-*.*s %-*.*s", UT_NAMESIZE, UT_NAMESIZE, up->ut_name, 141 UT_LINESIZE, UT_LINESIZE, up->ut_line); 142 (void)strftime(buf, sizeof(buf), "%c", localtime(&up->ut_time)); 143 buf[sizeof(buf) - 1] = '\0'; 144 (void)printf("%.12s", buf + 4); 145 if (*up->ut_host) 146 printf("\t(%.*s)", UT_HOSTSIZE, up->ut_host); 147 (void)putchar('\n'); 148 } 149 150 FILE * 151 file(name) 152 char *name; 153 { 154 FILE *ufp; 155 156 if (!(ufp = fopen(name, "r"))) 157 err(1, "%s", name); 158 return(ufp); 159 } 160