> But they are.

Did you remember to:

- check for the other spawned process exit code?

- waitpid for all process in the other process chain?

- propagate/handle signals, like for example SIGINT/SIGTSTP/SIGPIPE/SIGHUP forward and back signals?

- change stdio buffering mode?

- remember to count how many bytes actually were written by write, and blocking if not, before clobbing the 64kb of the pipe buffer size with another write?

- flush, then close all file descriptors left behind by the pipes when it ends?

It's for reasons like that, that I don't trust anything non-trivial, not-shell to use pipelines correctly.