Re: [Help-bash] Does the parent get the trap signal when the child is running in the foreground?

[Chet Ramey]

On 12/10/18 12:25 PM, Peng Yu wrote:
> Hi,
> 
> I am not sure if I understand the traps related with parent and child
> processes correctly.
> 
> I press Ctrl-C 5 times. The child gets SIGINT 5 times and the parent
> gets 1 once. But since Ctrl-C triggers SIGINT for the process group
> whose leader is the process started by main1.sh, why main1.sh only
> gets one signal? Thanks.

The parent receives 5 SIGINTs, but only runs the trap once, when the
child process completes.

Read https://www.cons.org/cracauer/sigint.html for more insight about the
options.

The parent shell shouldn't really do anything, since the child -- the
foreground process -- caught the SIGINT, handled it, and did not exit as a
result. However, backwards compatibility and user expectations being what
they are, the parent shell (main1.sh) runs the SIGINT trap as well.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    address@hidden    http://tiswww.cwru.edu/~chet/