Thank you for your post. The situation actually is like this. I have AIX clients and Linux clients. They are running a perl script that resides on a server . However instead of using the local Perl interpreter they are using the Perl on the server with NFS. Now the script on the server should check which OS the client has ( by checking $^O from within the script) and then decide which Perl path to choose . How do I deal with shebang line in this case?