usr.sbin/lastlogin/lastlogin.c

   1 /*
   2  * Copyright (c) 1996 John M. Vinopal
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed for the NetBSD Project
  16  *      by John M. Vinopal.
  17  * 4. The name of the author may not be used to endorse or promote products
  18  *    derived from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  25  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  27  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $NetBSD: lastlogin.c,v 1.4 1998/02/03 04:45:35 perry Exp $
  33  * $FreeBSD: src/usr.sbin/lastlogin/lastlogin.c,v 1.2.2.2 2001/07/19 05:02:46 kris Exp $
  34  */
  35
  36 #include <sys/user.h>
  37
  38 #include <err.h>
  39 #include <pwd.h>
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <time.h>
  43 #include <utmp.h>
  44 #include <utmpx.h>
  45 #include <unistd.h>
  46
  47 static  void    output(struct passwd *, struct lastlog *);
  48 static  void    outputx(struct passwd *, struct lastlogx *);
  49 static  void    usage(void);
  50
  51 int
  52 main(int argc, char **argv)
  53 {
  54         int     ch, i;
  55         long offset;
  56         FILE    *fp;
  57         struct passwd   *passwd;
  58         struct lastlog  last;
  59         struct lastlogx lastx;
  60
  61         while ((ch = getopt(argc, argv, "")) != -1) {
  62                 usage();
  63         }
  64
  65         if ((fp = fopen(_PATH_LASTLOG, "r")) == NULL)
  66                 err(1, "%s", _PATH_LASTLOG);
  67
  68         setpassent(1);  /* Keep passwd file pointers open */
  69
  70         /* Process usernames given on the command line. */
  71         if (argc > 1) {
  72                 for (i = 1; i < argc; ++i) {
  73                         if ((passwd = getpwnam(argv[i])) == NULL) {
  74                                 warnx("user '%s' not found", argv[i]);
  75                                 continue;
  76                         }
  77                         if ((getlastlogx(_PATH_LASTLOGX, passwd->pw_uid,
  78                             &lastx)) != NULL) {
  79                                 outputx(passwd, &lastx);
  80                                 goto done;
  81                         }
  82                         /* Calculate the offset into the lastlog file. */
  83                         offset = (long)(passwd->pw_uid * sizeof(last));
  84                         if (fseek(fp, offset, SEEK_SET)) {
  85                                 warn("fseek error");
  86                                 continue;
  87                         }
  88                         if (fread(&last, sizeof(last), 1, fp) != 1) {
  89                                 warnx("fread error on '%s'", passwd->pw_name);
  90                                 clearerr(fp);
  91                                 continue;
  92                         }
  93                         output(passwd, &last);
  94                 }
  95         }
  96         /* Read all lastlog entries, looking for active ones */
  97         else {
  98                 while ((passwd = getpwent()) != NULL) {
  99                         if ((getlastlogx(_PATH_LASTLOGX, passwd->pw_uid,
 100                             &lastx)) != NULL) {
 101                                 if (lastx.ll_tv.tv_sec == 0)
 102                                         continue;
 103                                 outputx(passwd, &lastx);
 104                         } else {
 105                                 offset = (long)(passwd->pw_uid * sizeof(last));
 106
 107                                 if (fseek(fp, offset, SEEK_SET)) {
 108                                         continue;
 109                                 }
 110                                 if (fread(&last, sizeof(last), 1, fp) != 1) {
 111                                         continue;
 112                                 }
 113                                 if (last.ll_time == 0)
 114                                         continue;
 115                                 output(passwd, &last);
 116                         }
 117                 }
 118 #if 0
 119                 for (i = 0; fread(&last, sizeof(last), 1, fp) == 1; i++) {
 120                         if (last.ll_time == 0)
 121                                 continue;
 122                         if ((passwd = getpwuid((uid_t)i)) != NULL)
 123                                 output(passwd, &last);
 124                 }
 125                 if (ferror(fp))
 126                         warnx("fread error");
 127 #endif
 128         }
 129
 130 done:
 131         setpassent(0);  /* Close passwd file pointers */
 132
 133         fclose(fp);
 134         exit(0);
 135 }
 136
 137 /* Duplicate the output of last(1) */
 138 static void
 139 output(struct passwd *p, struct lastlog *l)
 140 {
 141         printf("%-*.*s  %-*.*s %-*.*s   %s",
 142                 UT_NAMESIZE, UT_NAMESIZE, p->pw_name,
 143                 UT_LINESIZE+4, UT_LINESIZE+4, l->ll_line,
 144                 UT_HOSTSIZE, UT_HOSTSIZE, l->ll_host,
 145                 (l->ll_time) ? ctime(&(l->ll_time)) : "Never logged in\n");
 146 }
 147
 148 static void
 149 outputx(struct passwd *p, struct lastlogx *l)
 150 {
 151         printf("%-*.*s  %-*.*s %-*.*s   %s",
 152                 UT_NAMESIZE, UT_NAMESIZE, p->pw_name,
 153                 UT_LINESIZE+4, UT_LINESIZE+4, l->ll_line,
 154                 UT_HOSTSIZE, UT_HOSTSIZE, l->ll_host,
 155                 (l->ll_tv.tv_sec) ? ctime((&l->ll_tv.tv_sec)) : "Never logged in\n");
 156 }
 157
 158 static void
 159 usage(void)
 160 {
 161         fprintf(stderr, "usage: lastlogin [user ...]\n");
 162         exit(1);
 163 }