How can I standardize shell script header #! on different hosts?

Question

I manage a large number of shell (ksh) scripts on server A. Each script begins with the line...

#!/usr/bin/ksh

When I deploy to machine B, C, and D I frequently need to use a different shell such as /bin/ksh, /usr/local/bin/ksh or even /usr/dt/bin/ksh. Assume I am unable to install a new version of ksh and I am unable to create links in any protected directories such as /usr/local/bin. At the moment I have a sed script which modifies all the scripts but I would prefer not to do this. I would like to standardize the header so that it no longer needs to be changed from server to server. I don't mind using something like

#!~/ksh

And creating a link which is on every server but I have had problems with finding home using "~" in the past when using rsh (maybe is was ssh) to call a script (AIX specifically I think). Another option might be to create a link in my home directory and ensuring that it is first in my PATH, and simply using

#!ksh

Looking for a good solution. Thanks.

Answer 1

#! /usr/bin/env ksh

will use whatever ksh is in the user's path.

Answer 2

As rettops noted, you can use:

#!/usr/bin/env ksh

This will likely work for you. However, there can be some drawbacks. See Wikipedia on Shebang for a fairly thorough discussion.