Difference between ksh and sh

[Mohamed K Ahmed]

What is the difference betweenthe shells ksh and sh?
also /usr/bin/sh and /bin/sh?
The operating system is Tru64 Unix V 5.1B

Thanks

[Mark Grant · Accepted solution]

It's slightly more complicated than that. /usr/bin/sh is the old bourne shell and doesn't support a lot of stuff that the korn sheel does e.g job control, the [[ test, the $(mycommand) construct and a whole host of other things. The korn shell is far more functional and exciting and support command line editing etc etc etc.

However, Tru64 also has /usr/bin/posix/sh which retains compatbility with the bourne shell and yet has all the exciting functionality of the Korn shell. I believe that ksh is, in fact the posix shell on recent versions of the OS. Which shell you get is determined by the final field in /etc/passwd.

In other words, use the korn shell.

[RACAPE]

The shell ksh use library dynamic and the
sh use library static and this last is adviced for maintenance .