| /* Copyright (C) 1996 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public License as |
| published by the Free Software Foundation; either version 2 of the |
| License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public |
| License along with the GNU C Library; see the file COPYING.LIB. If not, |
| write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include <errno.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <utmp.h> |
| #include <sys/file.h> |
| #include <sys/stat.h> |
| |
| void |
| logwtmp (const char *line, const char *name, const char *host) |
| { |
| struct utmp ut; |
| struct stat st; |
| size_t written; |
| int fd; |
| |
| /* Open WTMP file. */ |
| fd = __open (_PATH_WTMP, O_WRONLY | O_APPEND); |
| if (fd < 0) |
| return; |
| |
| /* Set information in new entry. */ |
| memset (&ut, 0, sizeof (ut)); |
| #if _HAVE_UT_PID - 0 |
| ut.ut_pid = getpid (); |
| #endif |
| #if _HAVE_UT_TYPE - 0 |
| ut.ut_type = name[0] ? USER_PROCESS : DEAD_PROCESS; |
| #endif |
| strncpy (ut.ut_line, line, sizeof ut.ut_line); |
| strncpy (ut.ut_name, name, sizeof ut.ut_name); |
| #if _HAVE_UT_HOST - 0 |
| strncpy (ut.ut_host, host, sizeof ut.ut_host); |
| #endif |
| |
| #if _HAVE_UT_TV - 0 |
| __gettimeofday (&ut.ut_tv, NULL); |
| #else |
| time (&ut.ut_time); |
| #endif |
| |
| /* Try to lock the file. */ |
| if (__flock (fd, LOCK_EX | LOCK_NB) < 0 && errno != ENOSYS) |
| { |
| /* Oh, oh. The file is already locked. Wait a bit and try again. */ |
| sleep (1); |
| |
| /* This time we ignore the error. */ |
| __flock (fd, LOCK_EX | LOCK_NB); |
| } |
| |
| /* Remember original size of log file: */ |
| if (__fstat (fd, &st) < 0) |
| goto done; |
| |
| /* Write the entry. If we can't write all the bytes, reset the file |
| size back to the original size. That way, no partial entries |
| will remain. */ |
| written = __write (fd, &ut, sizeof (ut)); |
| if (written > 0 && written != sizeof (ut)) |
| ftruncate (fd, st.st_size); |
| |
| done: |
| /* And unlock the file. */ |
| __flock (fd, LOCK_UN); |
| |
| /* Close WTMP file. */ |
| __close (fd); |
| } |