Re: Add SHELL_EXIT_CODE to psql

On Sat, 31 Dec 2022 at 16:47, Corey Huinker <corey(dot)huinker(at)gmail(dot)com> wrote:

>
>> I wonder if there is value in setting up a psql on/off var
>> SHELL_ERROR_OUTPUT construct that when set to "off/false"
>> suppresses standard error via appending "2> /dev/null" (or "2> nul" if
>> #ifdef WIN32). At the very least, it would allow for tests like this to be
>> done with standard regression scripts.
>>
>
> Thinking on this some more a few ideas came up:
>
> 1. The SHELL_ERROR_OUTPUT var above. This is good for simple situations,
> but it would fail if the user took it upon themselves to redirect output,
> and suddenly "myprog 2> /dev/null" works fine on its own but will fail when
> we append our own "2> /dev/null" to it.
>

Rather than attempting to append redirection directives to the command,
would it work to redirect stderr before invoking the shell? This seems to
me to be more reliable and it should allow an explicit redirection in the
shell command to still work. The difference between Windows and Unix then
becomes the details of what system calls we use to accomplish the
redirection (or maybe none, if an existing abstraction layer takes care of
that - I'm not really up on Postgres internals enough to know), rather than
what we append to the provided command.