Re: [BUG?] binfmt_script: interpreted interpreter doesn't work

Pozsar Balazs (pozsy@uhulinux.hu)
Sun, 15 Sep 2002 21:13:30 +0200 (MEST)


On Sun, 15 Sep 2002, Hans-Peter Jansen wrote:

> > Consider these two scripts:
> >
> > /home/pozsy/a:
> > #!/usr/bin/perl
> > print <>;
> >
> > /home/pozsy/b:
> > #!/home/pozsy/a
> > "This is some text to printed out by the 'a' script"

> What's the problem?

I have a script written in perl, which interprets its input (or the files
in its arguments) [this is "a" in the above example]. I want to use this
script, as an interpreter to another "script" [the "b" in the above
example].

I well know bash, but this has nothing to do with shell coding.

Try my above example and you will understand what the problem is.
If you execute /home/pozsy/b, you _should_ get this as the output (2
lines) (the "a" program simply cats its input or argument files to its
output):
#!/home/pozsy/b
"This is some text to printed out by the 'a' script"

BUT this is what you get (1 line):
/home/pozsy/b: This is some text to printed out by the 'a' script: command
not found

This is because the kernel cannot execute the "/home/pozsy/b" script, and
then bash tries to interpret it itself. (but this in *not* what I want: I
want the "b" 'script' interpreted by the "a" script).
If you try this:
strace -f /home/pozsy/b
You will get this:
execve("/home/pozsy/b", ["/home/pozsy/b"], [/* 24 vars */]) = 0
strace: exec: Exec format error

The root of the problem is still that /home/pozsy/b cannot be execve'd.
That is a kernel problem.

-- 
pozsy

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/