2 or more processes on the write end of the same pipe

[Skaperen]

i want to start 2 or more processes with stdout of each writing to the write end of the same one pipe. my code will then read from the read end of that pipe (maybe many lines) and eventually kill or signal all the processes (so it also needs to get all of their process ID numbers). of course my code decides what executable (and args) to run in each.

there are tools to run processes. but they only make pipes with each having a different pipe. i want all the output to be combined into one single pipe so that the next read gets output from any.