toolbox: Add nohup command

	nandread \

	netstat \

	newfs_msdos \

	nohup \

	notify \

	printenv \

	ps \

#include <signal.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

int nohup_main(int argc, char *argv[])

{

    if (argc < 2) {

        fprintf(stderr, "Usage: %s [-n] program args...\n", argv[0]);

        return EXIT_FAILURE;

    }

    signal(SIGHUP, SIG_IGN);

    argv++;

    if (strcmp(argv[0], "-n") == 0) {

        argv++;

        signal(SIGINT, SIG_IGN);

        signal(SIGSTOP, SIG_IGN);

        signal(SIGTTIN, SIG_IGN);

        signal(SIGTTOU, SIG_IGN);

        signal(SIGQUIT, SIG_IGN);

        signal(SIGTERM, SIG_IGN);

    }

    execvp(argv[0], argv);

    perror(argv[0]);

    return EXIT_FAILURE;

}