[Help-bash] The best way to derefrence a variable whose name is stored in another variable.

[Peng Yu]

Hi I use the following code to test if the variable name stored in "x"
actually have any value set. But I am not sure if it is the best way
to do.

Does anybody know what is the best way to do so in bash?

#!/usr/bin/env bash

var=10
x=var

if [ "$(eval echo "\$$x")" ]
then
  echo "the variable '$x' has a value"
else
  echo "the variable '$x' has no value"
fi


x=nvar

if [ "$(eval echo "\$$x")" ]
then
  echo "the variable '$x' has a value"
else
  echo "the variable '$x' has no value"
fi



-- 
Regards,
Peng