running a script in korn shell

I'm learning bash and have discovered that the shell can only work with integers and not decimals.

I'd like to run my scripts in korn to account for this, but just now, when I tried to run my script, I got an error message that said 'no such file or directory,' even though when I'm in the shell it lists it. Can someone tell me what I'm doing wrong?

While I'm here, how do I change shells -- in case I'm in bash and want to go to the korn shell, or vice versa?

Also, (I'm using OSX Snow Leopard), and how do I make or check that bash is the default shell to open in -- in the Preferences tab of the Terminal application, where it says run command, what should be in there (I think I may have done something there inadvertently). And how do I check to see which shell is currently running?

While I'm here, can someone remind me what command or pipe allows the user to break up a standard output when it exceeds the number of lines on the terminal?

Just be sure to make your script executable:

chmod +x your_script

When changing shells just type:

bash

or

ksh

To know the default shell:

echo $SHELL

With regards to stdout, Just pipe it with "less" or "more"...

I'm still getting the error message when I try to run the script. I'm typing 'source (scriptname)

And how do I delete characters? If I try to use tab to complete the line, there is a character at the end of the command/line that is highlighted, and I can't use fn+delete key to get rid of it -- I get some funny looking characters, and I eventually have to press enter and type the entire command.

The most likely reason

source scriptname

failed is that "." is not in your path.
You can determine what is in your path by:

echo $PATH

If you want to just run the script with ksh, use:

ksh ./scriptname

(again, assuming that the script is in your current directory) instead of source scriptname..
Or, as previously posted, make the script executable and invoke it directly:

./scriptname

The script will have to start the correct "shebang" line:

#! /bin/ksh

or things won't work. More on shebang at Shebang (Unix) - Wikipedia, the free encyclopedia