[PATCH] ld.so: add an --argv0 option

[Florian Weimer]

* Mike Frysinger:

> On 23 Apr 2016 14:21, Florian Weimer wrote:
>> * Mike Frysinger:
>> > Sometimes when you run a program you want the argv[0] string passed to
>> > the app to be different than the actual path you used to load it.  We
>> > can't do this today with invoking via ld.so which can be limiting --
>> > some programs like to inspect their argv[0] and make decisions as to
>> > how it should (re)exec itself or helper tools.  For example, clang and
>> > gcc both do argv[0] inspection to support relocatable toolchains.
>> 
>> Interesting idea.  I think it's sufficiently to include this, but it
>> needs a ChangeLog entry and a test case.
>
> for the test, seems like i'll have to write a small C file that just
> displays its argv, and then another shell script which runs the ldso
> against that simple program and checks the output.  unless anyone has
> a simpler idea.

You'll need the shell script wrapper.

Supplying the expected value in another argument, with some prefix and
suffix character, and comparing argv[0] to the extracted orignal
argument, is likely simpler than writing argv[0] to standard output
and reading it back from the shell script.