Determine if relative or absolute path in shell program

linux, path, shell

Solution

if [[ "$0" = /* ]]
then
   : # Absolute path
else
   : # Relative path
fi

Problem

As stated in the title, I need to determine when a program is ran if the path is relative or absolute: ``` ./program #relative dir/dir2/program #relative ~User/dir/dir2/program #absolute /home/User/dir/dir2/program #absolute ``` This are my test cases. How exactly could I go about doing this in a shell program? Or more generally, how to check if a path, `$0` in this case, is relative or absolute?

Original source