/* vi: set sw=4 ts=4: */ /* pidfile.c * * Functions to assist in the writing and removing of pidfiles. * * Russ Dill September 2001 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "common.h" static const char *saved_pidfile; static void pidfile_delete(void) { if (saved_pidfile) unlink(saved_pidfile); } int pidfile_acquire(const char *pidfile) { int pid_fd; if (!pidfile) return -1; pid_fd = open(pidfile, O_CREAT|O_WRONLY|O_TRUNC, 0644); if (pid_fd < 0) { bb_perror_msg("cannot open pidfile %s", pidfile); } else { lockf(pid_fd, F_LOCK, 0); if (!saved_pidfile) atexit(pidfile_delete); saved_pidfile = pidfile; } return pid_fd; } void pidfile_write_release(int pid_fd) { if (pid_fd < 0) return; fdprintf(pid_fd, "%d\n", getpid()); lockf(pid_fd, F_UNLCK, 0); close(pid_fd); }