#!/usr/bin/perl -n
#
# Convert a line like:
#    #include "foo.bar.h"
# into 3 lines like:
#    #ifndef   foo_bar_h
#    #include "foo.bar.h"
#    #endif
# This handles the simplest case of a conditional #include. This isn't
# really  necessary,  of  course, if the programmer has done the usual
# trick within foo.bar.h:
#    #ifndef foo_bar_h
#    #define foo_bar_h
#       ...
#    #endif
# Still, it can be useful at times, especially as  documentation,  and
# it does speed up compilation somewhat.
#
if (/#\s*include(\s+)"(.*)"/) {
	($f = $2) =~ s/\W/_/g;
	print "#ifndef$1  $f\n";
	print;
	print "#endif\n";
} else {
	print;
}