cannot execute binary file


I'm new to hMetis and have just downloaded it (and unzipped and untarred) on a Mac.
I've tried to test it by typing:

./shmetis s13207P.hgr 4 5

but I get:

-bash: ./shmetis:cannot execute binary file

I've set the permissions right (chmod 777 shmetis).
I have the same problem with hmetis and khmetis.

Any ideas?
It would be really great if I could get this working soon!