Re: bash 4.4 infinite loop while handling SIGTTIN

[Chet Ramey]

On 11/28/16 4:11 AM, pasthelod@gmail.com wrote:
> Hello,
> 
> I'm using this package: bash_4.4-2ubuntu1_amd64.deb ( 
> http://de.archive.ubuntu.com/ubuntu/pool/main/b/bash/bash_4.4-2ubuntu1_amd64.deb
>  ), but the same behavior happens with bash 4.3.
> 
> This seems to be the bug (feature?): 
> http://stackoverflow.com/questions/13718394/what-should-interactive-shells-do-in-orphaned-process-groups
> 
> I experience the bug when I launch Atom (a text editor so fancy it takes ages 
> to start, maybe that's why it waits for an infinite loop ... 
> https://github.com/atom/atom/issues/13317 ).
> 
> Any thoughts on this? Is this something unavoidable by bash, or it's a bug? 
> (Maybe it's a known bug?)

Basically, the problem is how to run a interactive shell that reads from
the tty when you're not a member of the foreground process group.  The bash
strategy will get you the default behavior for SIGTTIN, which will stop
the process.  The assumption is that there will be some parent process
willing to handle the stop, not just automatically send a SIGCONT, and bash
expects to be started with SIGTTIN set to the default disposition, not
blocked.

Chet


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