Executing a File Copying program written in C in terminal

Question

This is the code:

#include<stdio.h>

main(){
        int c;
        c = getchar();
        while( c != EOF ){
                putchar(c);
        }
}

I have made another file named "AFile" using vim.

To display the contents of "AFile" using my program, what command do I write in the terminal?

Answer 1

Your program reads from STDIN (fd 0), so you need to provide data at via stdin. In most shells, this can be done with the redirect operator < :

./yourprogram < inputfile

Another way would be using a pipe, but it is generally not recommended, because it needs to start an unnecessary second process:

cat inputfile | ./yourprogram