I have already posted the question. Because previous post has sinked so that I have to ask the question again. I created the script and chmod it as 755. The ksh shell is in bin. Now I typed ./script_name.ksh to execute the script in the directory of that script. The return message was: Ksh: ./script_name.ksh: Not found. What does this mean? I typed script name correctly. I am really confused by this. Anyone could give ma a hand? Thanks a lot.

Also, another question for execution permission: if a folder's permission show like: drwxr-sr-x, what is group's r-s, The user's rwx=7, other's r-x=5, I couldn't find what is group's r-s. Please advise. Thanks again.

Try with the the following in line 1 of your script :
Jean-Pierre.

Yes, #! /bin/ksh is on the top of the script.

Have you looked to see if there are hidden characters in your script name?
You could check by doing somthing like

#ls | cat -v

If you see odd stuff in your name then that could be why?

Make absolutely sure that the /bin/ksh or the /usr/bin/ksh file exists and that you are referring to the correct file in your script. This error is what is encountered when the interpreter is not found.

As for your question about the directory permissions, please go through the tutorials. Perderabo has written an excellent tutorial on file permissions.

Andrek and blowtorch:

Thanks so much for your advice. I followed to check script name and ksh files in /bin/ksh and in /usr/bin/ksh. ksh files exist in these directories and script name has no hidden characters. Then I tried to kick it off. It still told me 'Not found'. Why do I check ksh files existing? Do I need to register my script in these ksh files or something else? I am confused by this. Any idea?

Can you post the script? Atleast the first 15 or so lines? And also, post the output of 'ls -ld /usr/bin/ksh /bin/ksh /bin /usr/bin'.