Re: [Tinycc-devel] env executable examples

[Michael Matz]

Hi,

On Thu, 10 May 2012, grischka wrote:

> > [1] See commit 27a428cd0fae475d7377e1dbe218c064ee217d85
> >
> > Basically /usr/bin/env tcc -run will try to find "tcc -run" which is then 
> > obviously not found. Should we go back to the solution proposed in [2] or 
> > do you have another idea?
>
> Why not use just
>
>         #!tcc -tun

Because shebangs are interpreted by the kernel VFS, which doesn't know 
about $PATH, and hence won't find 'tcc' in any path (and therefore the 
execution will fail).  That's what env(1) was intended for, but the linux 
kernel unfortunately supports only exactly one (optional) argument for the 
interpreter, i.e. it breaks with two and more arguments like when the 
shebang is "#!env firstarg secondarg".  So, all in all, when you use an 
meta-interpreter (like env) that somehow needs the name of the real 
interpreter as argument (tcc in this case) you can't give further 
arguments to that real interpreter (-run here).

> Otherwise I'd suggest to revert to the original
>
>         #!/usr/local/bin/tcc -tun

Which again would have the problem of hardcoding the path to tcc into the 
"scripts".  You need a meta-interpreter for finding the name of the real 
interpreter, and you can't give further arguments to it.  Hence the best 
suggestion up to now was to create a wrapper script called tcc-run (just 
calling "exec tcc -run $1" on its argument), which would be used as 
argument to the 'env' shebang.

Of course, one could also decide to not care, but IMHO Davids above 
suggestion (helper script) is the most satisfying one, given the sorry 
circumstances.


Ciao,
Michael.