Re: binfmt_script and ^M

[Paul Flinders]

Andreas Schwab wrote:

> Paul Flinders <paul@dawa.demon.co.uk> writes:
>
> |> Andreas Schwab wrote:
> |>
> |> > This [isspace('\r') == 1] has no significance here.  The right thing to
> |>
> |> > look at is $IFS, which does not contain \r by default.  The shell only 
> splits
> |>
> |> > words by "IFS whitespace", and the kernel should be consistent with it:
> |> >
> |> > $ echo -e 'ls foo\r' | sh
> |> > ls: foo: No such file or directory
> |>
> |> The problem with that argument is that #!<interpreter> can be applied
> |> to more than just shells which understand $IFS, so which environment
> |> variable does the kernel pick?
>
> The kernel should use the same default value of IFS as the Bourne shell,
> ie. the same value you'll get with /bin/sh -c 'echo "$IFS"'.  This is
> independent of any settings in the environment.
>
> |> It's a difficult one - logically white space should terminate the 
> interpreter
>
> No, IFS-whitespace delimits arguments in the Bourne shell.

Way back whenever processing #! was moved from the
shell to the kernel** this argument would have made sense -
today I'm not so sure.

But I'm quite happy for the kernel to use just space and
tab if it wishes, or anything else for that matter but it _is_
confusing that the error code doesn't distinguish problems
with the script from problems with the interpreter.

**Did linux ever rely on the shell for this?