#include <unistd.h>
#include <stdio.h>
#include <sys/mman.h>

#define MCL_FOREVER 	4

int main(int argc, char *argv[], char *envp[])
{
	int rc;
	int c, do_fork = 0;

	while ((c = getopt(argc, argv, "f")) != -1) {
		switch(c) {
		case 'f':
			do_fork = 1;
			break;
		default:
			printf("usage:\t%s [-f] program_to_exec\n", argv[0]);
		}
	}
	argv += optind;

	rc = mlockall(MCL_FUTURE|MCL_FOREVER);
	if (rc == -1)
		perror("mlockall");

	if (do_fork) {
		int pid = fork();
		if (pid > 0)
			exit(0);
		else if (pid < 0) {
			perror("fork");
			exit(1);
		}
	}
	execve(argv[0], argv, envp);
	perror("execve");
	exit(1);
}