gistfile1.txt

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

int main(int argc, char *argv[]) {
    int fd_orig;
    int fd_dup;
    char c;

    fd_orig = open("/etc/debian_version", O_RDONLY);
    if (fd_orig < 0) {
        fprintf(stderr, "Open failed\n");
        exit(1);
    }
    fd_dup = dup(fd_orig);

    if (fd_dup < 0) {
        fprintf(stderr, "Dup failed\n");
        exit(1);
    }

    printf("Original\n");
    while (read(fd_orig, &c, 1)) {
        printf("%c", c);
    }
    printf("Dupped\n");
    while (read(fd_dup, &c, 1)) {
        printf("%c", c);
    }

    return 0;
}