#include <stdint.h>
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <unistd.h>

int main(int argc, char **argv) {
	if(argc < 3) {
		fprintf(stderr, "Usage: %s pidfile command [arguments]\n", argv[0]);
		return 1;
	}

	const char *pidfilename = argv[1];
	FILE *pidfile = fopen(pidfilename, "w");
	if(pidfile == NULL) {
		perror("fopen (opening pidfile)");
		return 1;
	}

	pid_t own_pid = getpid();
	
	if(fprintf(pidfile, "%ji\n", (intmax_t) own_pid) < 0) {
		perror("fprintf (printing pid)");
		fclose(pidfile);
		return 1;
	}

	if(fclose(pidfile) != 0) {
		perror("fclose (pidfile)");
		return 1;
	}

	char **daemon_argv = &argv[2];
	const char *daemon_command = daemon_argv[0];

	execvp(daemon_command, daemon_argv);

	perror("execvp");
	return 1;
}