Question

I pass a string as an argument to a shell script. and the shell script should tell me if the passed argument is a variable

something like this

if [ ! -z ${$1} ] ; then  
echo yes! $1 is a variable and its value is ${$1}  
fi

but this gives me bad substitution err..

I definitely know i’m missing something.. help me out!

Eg usage:

$ myscript.sh HOME  
yes! HOME is a variable and its value is /home/raj

Answer 1

The syntax for this is:

${!VAR}

Example:

$ function hello() { echo ${!1}; }
$ hello HOME
/home/me