Mimic the unix pipe mechanism.
The program must be executed as follows: ./pipex file1 cmd ... cmd_n file2
In bash it will look like this: < file1 cmd | ... | cmd_n > file2
The program is able to handle multiple as well as a single pipe.
During this project I used some interesting library functions: pipe(), fork(), dup2(). In addition, I learned the importance of handling the file descriptors properly.