#include <ctype.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <unistd.h>

FILE *f;

void cleanup(int sig)
{
			printf("\n");
			if (f)
				fclose(f);
			exit(EXIT_SUCCESS);
}

int main(int argc, char **argv)
{

			if (argc != 2) {
				fprintf(stderr, "Usage: %s len\n", argv[0]);
				return (EXIT_FAILURE);
			}

			signal(SIGINT, cleanup);

			long nof_chars = strtod(argv[1], NULL);
			char buf[nof_chars+1];

			if (!(f = fopen("/dev/random", "r"))) {
				fprintf(stderr, "fopen");
				return (EXIT_FAILURE);
			}

			while (1) {
				long nof_read = 0;
				while (nof_read < nof_chars) {
					fread(&buf[nof_read], 1, 1, f);
					if (isprint(buf[nof_read])) {
						nof_read++;
					}
				}
				buf[nof_chars] = '\0';
				printf("%s\n", buf);
				printf("Press Enter to continue, or ctrl-c to interrupt.");
				getc(stdin);
			}

			fclose(f);

			return (0);
}