Question $3.$ Write a C$/$C$++$ program that replicates the functionality of the Unix pipeline command

$ps xao sid $|$ sort $-$u$|$wc $-$l

This command counts the number of unique session IDs currently active on the system. Your implementation should focus on process creation and file descriptor management. Create three separate processes corresponding to each part of the pipeline $($ps$,$ sort, and wc$).$ Each process should execute the respective command as a new program. Your primary task is to ensure proper

$1$

control and redirection of file descriptors to mimic the behavior of the pipe $($I$)$ operator in a Unix shell. Remember, the goal is not to reimplement the commands themselves but to orchestrate their execution and intercommunication in a $\frac{C}{C}++$ program.