Check variable has been set

: ${VAR:?unset variable}
Works in all shells. Does not require a test. Handles like an assertion.
Sample Output
sh: VAR: unset variable

By: arcege
2009-09-14 19:41:01

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What Others Think

Thanks a lot for sharing the code that helps in checking the variable and this is really a good page to follow especially for the programmers as they always help us in clearing out regarding the programming I really like this page lot emergency kit for home
Kaitlyn · 80 weeks and 6 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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