lib/libutil/logout.c

   1 /*-
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)logout.c 8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libutil/logout.c,v 1.6.2.2 2000/09/20 09:54:16 jkh Exp $
  31  * $DragonFly: src/lib/libutil/logout.c,v 1.5 2007/12/30 13:44:33 matthias Exp $
  32  */
  33
  34 #include <sys/types.h>
  35 #include <sys/time.h>
  36
  37 #include <fcntl.h>
  38 #include <utmp.h>
  39 #include <unistd.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42
  43 #include "libutil.h"
  44
  45 typedef struct utmp UTMP;
  46
  47 int
  48 logout(const char *line)
  49 {
  50         int fd;
  51         UTMP ut;
  52         int rval;
  53
  54         if ((fd = open(_PATH_UTMP, O_RDWR, 0)) < 0)
  55                 return(0);
  56         rval = 0;
  57         while (read(fd, &ut, sizeof(UTMP)) == sizeof(UTMP)) {
  58                 if (!ut.ut_name[0] || strncmp(ut.ut_line, line, UT_LINESIZE))
  59                         continue;
  60                 bzero(ut.ut_name, UT_NAMESIZE);
  61                 bzero(ut.ut_host, UT_HOSTSIZE);
  62                 (void)time(&ut.ut_time);
  63                 (void)lseek(fd, -(off_t)sizeof(UTMP), L_INCR);
  64                 (void)write(fd, &ut, sizeof(UTMP));
  65                 rval = 1;
  66         }
  67         (void)close(fd);
  68         return(rval);
  69 }