The method for making up the sources database for help is unfortunately
not entirely automatic.  One would like to have a program that would
search from the root directory of the distributed programs for all
"programs", as distinct from subroutine files.  This unfortunately is not
easy due to our tendency to put subroutine files in directories
with their programs.  Also, it is nice to mention the source directories
of the various libraries, even though there is no "program" for them.

With this in mind, the way to update the sources database is as follows:

% find /mnt/carl/src \( -name '*.c' \) -print > helpcsrc
% vi helpcsrc
	edit out subroutine entries,
	reduce library entries to just the name of the library,
	replace the directory prefix /mnt/carl/src with m4SRCDIR:
		:1,$s:/mnt/carl/src:m4SRCDIR:
	ZZ
% rm -f helpfiles/sources
% foreach n (`cat helpcsrc`)
echo $n > helpfiles/sources/${n:t}
end
% foreach n (helpfiles/sources/*)
if (${n:x} != "") mv $n ${n:x}
end