How to warn for the use of unset variables in a korn shell script

Posted by Lepu on Stack Overflow See other posts from Stack Overflow or by Lepu
Published on 2008-11-28T10:11:31Z Indexed on 2010/04/25 6:03 UTC
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Filed under:

ksh

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shell

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scripting

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unix

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linux

Is there any way to throw errors or warnings in a korn shell script to prevent the use of unset variables ? Let's assume I have a temporary folder that I want to remove.

TEMP_FILES_DIR='/app/myapp/tmp'
rm -Rf $TEMP_FILE_DIR #notice the misspelling

How to prevent this kind of mistakes before they actually happen?

I know the script should check for file existence and empty string before attempting to remove, this is just a silly example to illustrate a mistake that could have been avoided with some warnings. I don't know if this feature exists in ksh. If it does exist, how do you turn it on?

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