- https://brandonwamboldt.ca/how-linux-pipes-work-under-the-hood-1518/
- http://www.cplusplus.com/reference/cstring/strtok/
- https://brennan.io/2015/01/16/write-a-shell-in-c/
- https://www.gnu.org/software/bash/manual/html_node/Pipelines.html#Pipelines
- https://www.geeksforgeeks.org/signals-c-set-2/
- https://www.geeksforgeeks.org/pipe-system-call/