Bash : expression recursion level exceeded (error token is ...)

Question

I'm writing a program that prints the username and the number of times that the user has logged in, or prints "Unknown user" otherwise.

My code is the following:

iden=$1
c='last | grep -w -c $iden'
if (( $c > 1 ))
then
    echo "$iden $c"
else
    echo "Unknown user"
fi

And I keep getting this error:

-bash: ((: last | grep -w -c 123: expression recursion level exceeded (error token is "c 123")

Answer 1

To store the output of a command in a variable you need to say var=$(command). Hence, use:

c=$(last | grep -w -c "$iden")  # always good to quote the variables

instead of

c='last | grep -w -c $iden'

If you are learning Bash scripting, it is always handy to paste your code in ShellCheck to see the problems you may have.