lib/libutil/logout.c

   1 /*      $NetBSD: logout.c,v 1.16 2005/08/27 17:07:17 elad Exp $ */
   2
   3 /*
   4  * Copyright (c) 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)logout.c    8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: logout.c,v 1.16 2005/08/27 17:07:17 elad Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include <sys/types.h>
  42 #include <sys/time.h>
  43
  44 #include <assert.h>
  45 #include <fcntl.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <time.h>
  49 #include <unistd.h>
  50 #include <util.h>
  51 #include <utmp.h>
  52
  53 int
  54 logout(const char *line)
  55 {
  56         int fd, rval;
  57         struct utmp ut;
  58
  59         _DIAGASSERT(line != NULL);
  60
  61         if ((fd = open(_PATH_UTMP, O_RDWR, 0)) < 0)
  62                 return(0);
  63         rval = 0;
  64         while (read(fd, &ut, sizeof(ut)) == sizeof(ut)) {
  65                 if (!ut.ut_name[0] || strncmp(ut.ut_line, line,
  66                                               (size_t)UT_LINESIZE))
  67                         continue;
  68                 memset(ut.ut_name, 0, (size_t)UT_NAMESIZE);
  69                 memset(ut.ut_host, 0, (size_t)UT_HOSTSIZE);
  70                 (void)time(&ut.ut_time);
  71                 (void)lseek(fd, -(off_t)sizeof(ut), SEEK_CUR);
  72                 (void)write(fd, &ut, sizeof(ut));
  73                 rval = 1;
  74         }
  75         (void)close(fd);
  76         return(rval);
  77 }