Correct way of using getopts

Question

Executing following script gives error for mkdir command

PATH=/root
while getopts "r" name;
do
    case $name in
        r)
            PATH=/home
            ;;
        *)
            echo "Usage: $0 -r"
            ;;
    esac
done

echo $PATH
mkdir new

error:

./test.sh: line 15: mkdir: command not found

What's wrong in this script ?

Answer 1

Your problem doesn't really have anything to do with getopts.

The problem is the first line:

PATH=/root

or, if it's executed, this line:

PATH=/home

This sets the search path for commands to just the /root or /home directory. (Typically neither of those directories contains any commands).

Setting $PATH throws away the previous value. mkdir is probably in /bin, but since /bin is no longer in $PATH, the shell can't find it.

You don't get an error on the getopts command because it's built into the shell you're using.

If you want to add /root to your $PATH, use:

PATH="/root:$PATH"

or

PATH="$PATH:/root"

But nothing in your script appears to depend on having /root in your $PATH. Why are you doing PATH=/root in the first place? If you're trying to set your current working directory to /root or /home, you want the chdir command.