is there a way I can do the same thing using fork and exec?

As forking uses threads on my system, I've never explored it's use to any great extent.

It is probably possible using some arrangement whereby the original process sets up a separate STDOUT/STDIN prior to forking each command and then uses select to read the ouput from the child processes back into the parent for further processesing, but I am the wrong person to be advising on that.

Hopefully someone with more experience of the fork & exec style of coding will step up and provide an example solution.

I would also learn a lot from a worked example of this.