Re: Separating stdout and stderr

[Christophe Lyon]

On 31 March 2016 at 16:11, Christophe Lyon <address@hidden> wrote:
> On 31 March 2016 at 12:20, Ben Elliston <address@hidden> wrote:
>> On Thu, Mar 31, 2016 at 12:11:59PM +0200, Christophe Lyon wrote:
>>
>>> But since we currently have "|&cat", we do redirect stderr, so the
>>> "and that standard error is not redirected" claude above is not
>>> fulfilled. Do you know what happens in this case?
>>
>> No, but I would suggest that it is cleaner and more portable to use
>> Tcl exec's own way of doing this:
>>
>> 2>@1
>>     Standard error from all commands in the pipeline is redirected to
>>     the command result. This operator is only valid at the end of the
>>     command pipeline.
>>
>> This is used like an option, before the actual command.
>>
>> Give that a go. It might work better.
>>
>
> I tried it, and saw no change in a small manual run.
>
> Anyway, as Maxim explained better, this is going to merge the
> 2 streams on the builder, not on the board which actually
> runs the test. So I think embedding the "2>&1" as part of
> command executed remotely is better.
>
> I need to check how I can run a full validation with this
> change in our environment.
>

For the record, I identified what caused several random results in
our setup. That's because we use 'ssh -tt' to access the remote tester.

The use of '-tt' was an attempt to workaround potential stdout/stderr
problems by forcing a remote testing environment as close as
possible to a native one.

Using 'ssh -t' seems to work better: the random results have disappeared.

I will run a few more tests to determine whether adding "2>&1" to
the remote command as discussed above is needed.

Thanks,

Christophe