/* 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); } /* Remeber 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); }