/* wydawca - automatic release submission daemon
   Copyright (C) 2007, 2009-2013 Sergey Poznyakoff

   Wydawca 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 3 of the License, or (at your
   option) any later version.

   Wydawca 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 wydawca. If not, see <http://www.gnu.org/licenses/>. */

#include "wydawca.h"

char *pidfile = LOCALSTATEDIR "/run/wydawca.pid";
int force_startup;

void
remove_pidfile(void)
{
	unlink(pidfile);
}

void
check_pidfile()
{
	FILE *fp = fopen(pidfile, "r+");

	if (fp) {
		unsigned long pid = -1;
		if (fscanf(fp, "%lu\n", &pid) != 1) {
			wy_log(LOG_ERR, _("malformed pidfile %s"), pidfile);
			if (!force_startup)
				exit(EX_UNAVAILABLE);
		} else {
			if (kill(pid, 0)) {
				if (errno != ESRCH) {
					wy_log(LOG_ERR,
					       _("cannot verify if PID %lu "
						 "is running: %s"),
					       pid, strerror(errno));
					if (!force_startup)
						exit(EX_UNAVAILABLE);
				}
			} else if (!force_startup) {
				wy_log(LOG_ERR,
				       _("another wydawca instance may "
					 "be running (PID %lu)"),
				       pid);
				exit(EX_UNAVAILABLE);
			}
		}
		wy_log(LOG_NOTICE, _("replacing pidfile %s (PID %lu)"),
		       pidfile, pid);
		fseek(fp, 0, SEEK_SET);
	} else if (errno != ENOENT) {
		wy_log(LOG_ERR, _("cannot open pidfile %s: %s"), pidfile,
		       strerror(errno));
		exit(EX_UNAVAILABLE);
	} else {
		fp = fopen(pidfile, "w");
		if (!fp) {
			wy_log(LOG_ERR,
			       _("cannot open pidfile %s for writing: %s"),
			       pidfile, strerror(errno));
			exit(EX_UNAVAILABLE);
		}
	}
	fprintf(fp, "%lu\n", (unsigned long)getpid());
	fclose(fp);
}