# Get os name via uname.
_myos="$(uname)"
 
# Add alias using the OS.
case $_myos in
  Linux) alias foo='/path/to/linux/bin/foo';;
  FreeBSD|OpenBSD) alias foo='/path/to/bsd/bin/foo' ;;
  SunOS) alias foo='/path/to/sunos/bin/foo' ;;
  *) ;;
esac