This is really a shell question, not a Perl question, but for reasons that are hopefully obvious, it can't be done in Perl.

In our NFS environment we have various different platforms (Linuxes and AIX) sharing a common filesystem. It's useful to have central builds of certain programs - Perl being a good example, because it lets us have centrally installed modules too.

So let's say that we have

/nfs/perl/5.10/centos4/bin/perl

and

/nfs/perl/5.10/centos5/bin/perl

(The user environment is automatically set up so that the correct perl for their host is in the path.)

What I want to do is create a

/nfs/perl/5.10/bin/perl

which checks the platform of the current host, and starts the correct perl interpreter. I want it to work in a hash-bang line, and support command line parameters etc. Basically it should be invisible to the user that they aren't hitting the actual Perl binary directly.

I thought I had this working, with this script: 

#!/bin/sh

. /etc/host.conf

exec /nfs/perl/5.10/${HOST_PLATFORM}/bin/perl "$@"

[download]

In fact, this seems to work on the majority of machines. But there are some machines where it doesn't work at all when used in a hash-bang line. Instead of starting perl and running the script with that, it tries to run the perl script through /bin/sh, with the entertaining but unproductive results that you would probably expect.

I can't see any pattern for which hosts work and which don't, though many have custom kernels which might be a factor.

Does anyone know of an alternative way to write this wrapper script which might be more reliable?

In reply to Can I write a transparent shell wrapper to start the correct build of Perl? by thparkth

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