[BusyBox] TAKE 2: Message on Startup: "sh: can't access tty; job control turned off"

[Stewart Brodie]

In message <15FDCE057B48784C80836803AE3598D53B8A0D at racerx.ixiacom.com>
          Dan Kegel <dkegel at ixiacom.com> wrote:

> From: Frank Hammond
>> ....
>> The boot disk seems to work ok in general, however when it starts up the
>> last message that shows before the shell prompt is:
>> 
>> sh: can't access tty; job control turned off
>> #
>> 
>>  I believe this is a Busybox message but I don't know whether this
>> message
>> is an error. Can anyone explain what the comments mean?? Is "job control
>> turned off" something important???

> Hey, if it works, it works...
> 
> If you want to understand that error message, you
> may need to look at the busybox source, and
> possibly add a few more prints.
> - Dan

The tests around the code that emits that message is rather strange
(shell/ash.c; revision 1.66; line 5994).  It goes:

  initialpgrp = tcgetpgrp(2);
  if (initialpgrp < 0) { ...; return; }
  if (initialpgrp == -1) ....
  
so the second test can never succeed.  I'm no expert when it comes to process
group things though, so I don't know what the right thing to do here is, or
indeed whether the code does behave correctly and the extra condition is
simply harmless.



-- 
Stewart Brodie, Senior Software Engineer
Pace Micro Technology PLC
645 Newmarket Road
Cambridge, CB5 8PB, United Kingdom         WWW: http://www.pacemicro.com/