>My quick and dirty workaround was to copy /usr/include/signal.h to
>/usr/include/sys/signal.h.  This corrected the "No such file or directory"
>error.

That's quick, but real dirty. Please remember to remove it.

The best way is to obtain the /usr/contrib/include hierarchy which will
include many of the missing items one needs to be able to port to MPE.
Steve, if you don't have the FREEWARE tape, let me know and I'll send
this to you directly under separate cover.

In the near future (RSN and all that), this will be publically available
on the net under CVS for anonymous access (I just gotta get the web pages
done and approved :-)).

>gcc -c  -I../os/unix -I../include -D_POSIX_SOURCE -D_SOCKET_SOURCE
-I/IX/PUB/mpe
>/inc  -DMPE -D_POSIX_SOURCE -D_SOCKET_SOURCE -DUSE_HSREGEX `../apaci`
ap_signal.

Here is a group of standard variables I always define for my ports:

export CFLAGS="-I/usr/contrib/include -DSYSV -D_POSIX_SOURCE -D_SOCKET_SOURCE \
  -D_MPEIX_SOURCE -D_MPEXL_SOURCE"
export CXXFLAGS="$CFLAGS"
export CPPFLAGS="$CFLAGS"
export LDFLAGS="-lsocket -lcurses -lsvipc"
export CC=gcc
export CPP="gcc -E"

The CFLAGS and LDFLAGS are pretty much essential before running a configure
script.