* Shell scripts
extension typically .sh
chmod a+rx foo.sh
./foo.sh or "sh foo.sh"
how #!/bin/sh works in scripts
	vs. regular a.out or ELF binaries
positional args $0-$n, $#, $*

* Makefiles

look for programs: which
	if test $? = 0  ; then OK; else BAD; fi
use Makefile.tmpl
use sed to autogen the Makefile
ranlib encoded in makefiles