fd, dup()/dup2() system call tutorial

In this video, we illusrate the basics of dup() and dup2() and how you can use these system calls to modify the file descriptors of your system. Modifying these file descriptors will allow us to change the direction of input and output of our program (e.g: instead of having our program read stdin from the terminal, we can have our program read stdin from our file, instead).