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 #include <sys/cdefs.h> 38 39 __FBSDID("$FreeBSD$"); 40 41 #ifndef lint 42 static const char copyright[] = 43 "@(#) Copyright (c) 1989, 1993\n\ 44 The Regents of the University of California. All rights reserved.\n"; 45 #endif 46 47 #ifndef lint 48 static const char sccsid[] = "@(#)who.c 8.1 (Berkeley) 6/6/93"; 49 #endif 50 51 #include <sys/types.h> 52 #include <sys/file.h> 53 54 #include <err.h> 55 #include <langinfo.h> 56 #include <locale.h> 57 #include <pwd.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <time.h> 62 #include <unistd.h> 63 #include <utmp.h> 64 65 static void usage __P((void)); 66 static void output __P((struct utmp *)); 67 static FILE *file __P((const char *)); 68 69 int 70 main(argc, argv) 71 int argc; 72 char **argv; 73 { 74 char *p; 75 struct utmp usr; 76 struct passwd *pw; 77 FILE *ufp; 78 char *t; 79 80 (void) setlocale(LC_TIME, ""); 81 82 switch (argc) { 83 case 1: /* who */ 84 ufp = file(_PATH_UTMP); 85 /* only entries with both name and line fields */ 86 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 87 if (*usr.ut_name && *usr.ut_line) 88 output(&usr); 89 break; 90 case 2: /* who utmp_file */ 91 ufp = file(argv[1]); 92 /* all entries */ 93 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 94 output(&usr); 95 break; 96 case 3: /* who am i */ 97 if (strcmp(argv[1], "am") 98 || (strcmp(argv[2], "I") && strcmp(argv[2], "i"))) 99 usage(); 100 101 ufp = file(_PATH_UTMP); 102 103 /* search through the utmp and find an entry for this tty */ 104 if ((p = ttyname(0))) { 105 /* strip any directory component */ 106 if ((t = rindex(p, '/'))) 107 p = t + 1; 108 while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1) 109 if (*usr.ut_name && !strcmp(usr.ut_line, p)) { 110 output(&usr); 111 exit(0); 112 } 113 /* well, at least we know what the tty is */ 114 (void)strncpy(usr.ut_line, p, UT_LINESIZE); 115 } else 116 (void)strcpy(usr.ut_line, "tty??"); 117 pw = getpwuid(getuid()); 118 (void)strncpy(usr.ut_name, pw ? pw->pw_name : "?", UT_NAMESIZE); 119 (void)time(&usr.ut_time); 120 *usr.ut_host = '\0'; 121 output(&usr); 122 break; 123 default: 124 usage(); 125 } 126 exit(0); 127 } 128 129 static void 130 usage() 131 { 132 (void)fprintf(stderr, "%s\n%s\n", 133 "usage: who [file]", 134 " who am i"); 135 exit(1); 136 } 137 138 void 139 output(up) 140 struct utmp *up; 141 { 142 char buf[80]; 143 static int d_first = -1; 144 145 if (d_first < 0) 146 d_first = (*nl_langinfo(D_MD_ORDER) == 'd'); 147 148 (void)printf("%-*.*s %-*.*s", UT_NAMESIZE, UT_NAMESIZE, up->ut_name, 149 UT_LINESIZE, UT_LINESIZE, up->ut_line); 150 (void)strftime(buf, sizeof(buf), 151 d_first ? "%e %b %R" : "%b %e %R", 152 localtime(&up->ut_time)); 153 (void)printf("%s", buf); 154 if (*up->ut_host) 155 printf("\t(%.*s)", UT_HOSTSIZE, up->ut_host); 156 (void)putchar('\n'); 157 } 158 159 static FILE * 160 file(name) 161 const char *name; 162 { 163 FILE *ufp; 164 165 if (!(ufp = fopen(name, "r"))) 166 err(1, "%s", name); 167 return(ufp); 168 } 169