Shell Programming and Scripting

for i in `seq 1 $num`
do
        . config.txt
        unset=mn
        mn=path_$i
        if [[ ! -d "$mn" ]];then
                echo $mn
        else
                echo somethings missing
        fi
done

mute@thedoctor:~/temp/awesomeness_evo$ cat config.txt
path_1=one
path_2=two
path_3=foo
num=3
mute@thedoctor:~/temp/awesomeness_evo$ ./script
path path_1=one does NOT exist.
path path_2=two does NOT exist.
path path_3=foo does NOT exist.
mute@thedoctor:~/temp/awesomeness_evo$ cat script
#!/bin/bash

. config.txt

for ((i = 1; i <= num; i++)); do
        mn=path_$i
        if [[ ! -d "${!mn}" ]]; then
                echo "path $mn=${!mn} does NOT exist."
                # exit?
        else
                echo "path $mn=${!mn} does exist."
        fi
done