bug-bash
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: signals ignored in a subshell


From: Chet Ramey
Subject: Re: signals ignored in a subshell
Date: Mon, 6 Apr 2020 09:24:27 -0400
User-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:68.0) Gecko/20100101 Thunderbird/68.6.0

On 4/6/20 8:03 AM, Oğuz wrote:

> Okay, you're right, in posix mode the behavior is as expected. However I
> still didn't get why job controls being enabled/disabled changes the way an
> interactive shell handles signals in posix mode. Like
> 
> $ set -o posix
> $
> $ trap 'echo foo' INT
> $
> $ read
> ^Cfoo
> $ sleep 5
> ^C
> $
> $ set +m
> $
> $ read
> ^Cfoo
> $ sleep 5
> ^Cfoo
> 
> Is there a race condition here or does posix mandate this behavior for
> built-in utilities?

When job control is enabled, commands are run in separate process groups,
and those process groups get terminal-generated signals like SIGINT. The
shell never sees them.

-- 
``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/



reply via email to

[Prev in Thread] Current Thread [Next in Thread]