daemon.c
1.89 KB
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/* GNU Mailutils -- a suite of utilities for electronic mail
Copyright (C) 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.
This 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General
Public License along with this library; if not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301 USA */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <mailutils/daemon.h>
#include <mailutils/errno.h>
#include <mu_umaxtostr.h>
static char *pidfile;
static pid_t current_pid;
int
mu_daemon_create_pidfile (const char *filename)
{
const char *pid_string;
int fd;
if (filename[0] != '/')
{
return EINVAL; /* failure */
}
if (pidfile)
free (pidfile);
pidfile = strdup (filename);
unlink (pidfile);
current_pid = getpid ();
if ((fd = open (pidfile, O_WRONLY | O_CREAT
| O_TRUNC | O_EXCL, 0644)) == -1)
{
return errno; /* failure */
}
pid_string = mu_umaxtostr (0, current_pid);
write (fd, pid_string, strlen (pid_string));
close (fd);
atexit (mu_daemon_remove_pidfile);
return 0;
}
void
mu_daemon_remove_pidfile (void)
{
if (getpid () == current_pid)
{
unlink (pidfile);
free (pidfile);
pidfile = NULL;
}
}