bash test check validate if variable is number

varNUM=12345; re='^[0-9]+$'; if ! [[ $varNUM =~ $re ]] ; then echo "error: Not a number"; fi
to test check if given variable is a digit / number
Sample Output
error: Not a number

By: aysadk
2019-07-26 09:15:37

What Others Think

Three things regarding the given solution: 1. It does not handle negative integers. 2. It does not handle the the '+' sign 3. No need to use 'if', i.e. here is shorter version of the original solution: varNUM=12A45; re='^[0-9]+$'; [[ ! $varNUM =~ $re ]] && echo "error: Not a number"
forouharid · 64 weeks and 2 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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