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

int main(int argc, char *argv[])
{
    FILE *fp;

    //see if file name is specified
    if (argc != 2) {
        printf("File name missing.\n");
    }

    if ((fp = fopen(argv[1], "r")) == NULL) {
        printf("Cannot open file.\n");
        exit(1);
    }

    // show it once
    while (!feof(fp)) {
        putchar(getc(fp));
    }
    rewind(fp);
    // show it twice
    while (!feof(fp)) {
        putchar(getc(fp));
    }
    fclose(fp);
    return  0;
}