I ran your script with bash and dash and both worked fine.

Control-C sends SIGINT to every process in the foreground process group. Non-interactive shells run everything in the same process group, so when that process group is the foreground process group, Control-C sends a SIGINT to that shell, to all of its children, to all of its children's children, etc.

This suggests to me that you are executing that code in an interactive environment, where each command runs in its own process group. This would put sleep in a different process group from its parent shell. Since sleep is then the only member of the foreground process group, it is the only process to be sent a signal.

Are you sourcing the script at a command prompt with . or source? If yes, that explains the behavior. sleep is in a process group separate from the shell which invoked it, so the shell is not sent the signal.

If you are not sourcing the script, be specific and tell us exactly what you're doing. Also, while the script is running, collect the pid, ppid, pgid, and stat information for the relevant commands and share it with us. For this, the following command will probably work on your system.

Code:

ps -o pid,ppid,pgid,stat,args -t /dev/pts/4

Change /dev/pts/4 to the actual terminal you're using (this can be determined by typing tty at its prompt).

Regards,
Alister