Run a script from anywhere

You want to type abspath, but the program is named abspath.sh. The problem is not regarding whether it is in the PATH, but the fact that you are simply not using its name to call it.

You have two options:

1. Type abspath.sh instead.
2. Rename the program to abspath.

This code is small enough that I would code it as a shell function:

abspath() {
    echo "$(dirname "$(readlink -e "$1")")/$(basename "$1")" 
} 

And yes you do want all those quotes.

set an alias by adding your command in .bashrc file.

alias abspath='sh /home/myuser/bin/abspath.sh'

And don't forget to source the file.