to build mawk:

make sure  there is an appropriate description of
your system in machine.h

set CFLAGS in the Makefile to pick the appropriate blob
in machine.h

run make



PS:
I expected to have bcopy() <-> memcpy()
hassles on 4.3BSD, but didn't
Is this right? or did someone add memcpy(), strchr() etc
   to that machine?
   If 4.3BSD in machine.h is wrong, let me know at
   brennan@bcsaic.boeing.com