Re: env: please add argv0 setting feature

[Pádraig Brady]

On 02/03/2023 12:34, matheus.a.m.moreira@gmail.com wrote:
> I'm using env to control a program's environment for testing purposes.
> It allows me control over arguments, environment and input.
>
>      env -i VARIABLE=value program argv1 argv2 argv3
>
> However, I also need control over the program name located at argv0.
>
>      # argv0 is set to "./program"
>      env -i VARIABLE=value ./program argv1 argv2 argv3
>
> I'd like to normalize it to "program" for testing purposes.
> I'd also like to be able to set it to other values.
> So it would be useful if env had support for it. Something like:
>
>      env --name program -i VARIABLE=value ./program argv1 argv2 argv3
>
> I tried to use bash for this but it didn't turn out well.
>
>      # Sets PWD and SHLVL and the latter apparently can't be unset
>      env -i VARIABLE=value bash -c 'exec -a program ./program'
>
>      # Sets env's argv0, not my program's
>      bash -c 'exec -a program env -i VARIABLE=value ./program'
>
> Are you open to receiving a patch for this feature?

This does seem appropriate for adding to env(1).

Well I'm a bit reluctant given bash supports this already.
Re using bash, the PWD and SHLVL issue seems like edge cases though
and not generally a problem? BTW it seems like SHLVL can be unset here.
Also for the record I notice one can do `ARGV0=blah command` in zsh.

Perhaps --title would be more appropriate, given "name" is mentioned
quite a bit already in the description.

An edge case is we may want to support allowing to specify a NULL argv[0].

cheers,
Pádraig