Finding the path to a executable?

[Alan]

Hello!  This may seem like a simple question, maybe an 
embarassing question but how would I fetch the absolute path to 
the directory where my executable is located?  My wording is 
known to be confusing so I will give an example:

cd ~/projects/program
dmd Program.d -ofProgram
That executable would be located in /home/alan/projects/program 
for example.  SO my question is how would I fetch the absolute 
path to that directory?

Thanks for any help!