khm on Nostr: these things are defined in posix: 1 - process group leader is the signal target, and ...

these things are defined in posix:
1 - process group leader is the signal target, and determines session membership
2 - if the process group leader exits, nothing much happens UNLESS that exit orphans the group (session-wise), in which case the kernel is supposed sighup+sigcont that group
3 - I have no idea, postix speaketh not