Converting scripts from Solaris korn shell to run on both Solaris and RHEL

paulfoel · 07-19-2013, 01:52 AM

First issue I can see is the header.

On Solaris, its /usr/bin/ksh, on RHEL its /bin/ksh.
I guess one way is to add symbolic line of /usr/bin/ksh on RHEL?

Then, I guess there are command differences. One idea has been to use uname to set an environment variable then enabling an IF statement to run different commands.

Any idea where I can get a list of different commands?

Also, anything else I need to think of?

druuna · 07-19-2013, 02:11 AM

Quote:

Originally Posted by paulfoel

First issue I can see is the header.

On Solaris, its /usr/bin/ksh, on RHEL its /bin/ksh.
I guess one way is to add symbolic line of /usr/bin/ksh on RHEL?

That should solve that specific problem. One possible problem that I can see: If /usr is mounted separately and the script runs during boot things might not work (/usr not being mounted yet).

Quote:

Then, I guess there are command differences. One idea has been to use uname to set an environment variable then enabling an IF statement to run different commands.

This might be the core of your "problem". If these are simple scripts you might decide to put both versions into one script. If the scripts are more complicated I would personally got for 2 scripts, one for RHEL and one for Solaris. This would reduce the possibility of making cross-over mistakes and would be easier to maintain (even if you have/add lots of comments).

Quote:

Any idea where I can get a list of different commands?

You can use the Rosetta Stone for Unix and do have a look at the man pages. Some commands might have the same name and general functionality, but some options might not be present on either RHEL or Solaris.

Quote:

Also, anything else I need to think of?

Maybe to obvious: Do make sure you use the same KSH on both Solaris and RHEL (there are 2 major ones: AT&T's ksh and pdksh).

David the H. · 07-19-2013, 08:49 AM

"#!/usr/bin/env ksh" would probably do just as well. Let the system find it for you if it can.

As long as ksh is guaranteed to be installed on all involved systems, the shell syntax probably won't need to change much, if at all. But if you can't ensure that, then you'd have to fall back to the much more limited posix shell. I'm assuming that that won't be necessary though.

As for making the commands used compatible, probably the best thing to do is write up some functions to decide between them.

Code:

current_os=$( uname )

find(){
    case $current_os in

        Linux) command /path/to/linux/find <syntax for linux> ;;

        Solaris) command /path/to/solaris/find <syntax for solaris> ;;

        *) echo "What kind of rinky-dink OS are we running here?" ; return 1 ;;

    esac
}

You may have to get fancy in some cases, to get the input arguments to the places they need to be, or to emulate commands that don't exist on one or the other OS.

You could also set the function definitions in an external file and source that into all of your scripts (or AIUI ksh also has a function loading system you might be able to use?).