lib/libutil/logwtmp.c

   1 /*      $NetBSD: logwtmp.c,v 1.14 2003/08/07 16:44:59 agc 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[] = "@(#)logwtmp.c   8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: logwtmp.c,v 1.14 2003/08/07 16:44:59 agc Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include <sys/types.h>
  42 #include <sys/file.h>
  43 #include <sys/time.h>
  44 #include <sys/stat.h>
  45
  46 #include <assert.h>
  47 #include <string.h>
  48 #include <time.h>
  49 #include <unistd.h>
  50 #include <utmp.h>
  51 #include <util.h>
  52
  53 void
  54 logwtmp(const char *line, const char *name, const char *host)
  55 {
  56         struct utmp ut;
  57         struct stat buf;
  58         int fd;
  59
  60         _DIAGASSERT(line != NULL);
  61         _DIAGASSERT(name != NULL);
  62         _DIAGASSERT(host != NULL);
  63
  64         if ((fd = open(_PATH_WTMP, O_WRONLY|O_APPEND, 0)) < 0)
  65                 return;
  66         if (fstat(fd, &buf) == 0) {
  67                 (void) strncpy(ut.ut_line, line, sizeof(ut.ut_line));
  68                 (void) strncpy(ut.ut_name, name, sizeof(ut.ut_name));
  69                 (void) strncpy(ut.ut_host, host, sizeof(ut.ut_host));
  70                 (void) time(&ut.ut_time);
  71                 if (write(fd, &ut, sizeof(struct utmp)) != sizeof(struct utmp))
  72                         (void) ftruncate(fd, buf.st_size);
  73         }
  74         (void) close(fd);
  75 }