First pass at making up an automagical usage message extractor, which

will be used (when it works) to autogenerate documentation.  Based on
code written by Mark Whitley.

docs/autodocifier.pl

@@ -0,0 +1,88 @@
+#!/usr/bin/perl -w
+#
+# autodocufier.pl - extracts usage messages from busybox usage.c and
+# pretty-prints them to stdout.
+
+use strict;
+
+my $line;
+my $applet;
+my $count;
+my $full_usage;
+
+open(USAGE, 'usage.h') or die "usage.h: $!";
+
+while (defined($line = <USAGE>)) {
+	$count=0;
+	if ($line =~ /^#define (\w+)_trivial_usage/) {
+		# grab the applet name
+		$applet = $1;
+		print "\n$applet:\n";
+
+		while (defined($line = <USAGE>)) {
+			if ( $count==0 ) {
+			    $count++;
+			    print "\t$applet ";
+			} else { print "\t"; }
+			$full_usage = $applet . "_full_usage";
+			last if ( $line =~ /$full_usage/ );
+			# Skip preprocessor stuff
+			next if $line =~ /^\s*#/;
+			# Strip the continuation char
+			$line =~ s/\\$//;
+			# strip quotes off
+			$line =~ s/^\s*"//;
+			$line =~ s/"\s*$//;
+			# substitute escape sequences
+			# (there's probably a better way to do this...)
+			$line =~ s/\\t/	/g;
+			$line =~ s/\\n//g;
+			# fix up preprocessor macros
+			$line =~ s/USAGE_\w+\([\s]*?(".*?").*?\)/$1/sg;
+			# Strip any empty quotes out
+			$line =~ s/"[\s]*"//sg;
+			# strip line end quotes, again
+			$line =~ s/^\s*"//;
+			$line =~ s/"\s*$//;
+
+			# Finally, print it
+			print "$line\n";
+		}
+		printf("\n");
+		while (defined($line = <USAGE>)) {
+			if ( $count==0 ) {
+			    $count++;
+			    print "\t$applet ";
+			} else { print "\t"; }
+			# we're done if we hit a line lacking a '\' at the end
+			#last if ! $line !~ /\\$/;
+			if ( $line !~ /\\$/ ) {
+			    #print "Got one at $line\n";
+			    last;
+			}
+			# Skip preprocessor stuff
+			next if $line =~ /^\s*#/;
+			# Strip the continuation char
+			$line =~ s/\\$//;
+			# strip quotes off
+			$line =~ s/^\s*"//;
+			$line =~ s/"\s*$//;
+			# substitute escape sequences
+			# (there's probably a better way to do this...)
+			$line =~ s/\\t/	/g;
+			$line =~ s/\\n//g;
+			# Automagically #define all preprocessor lines
+			#$line =~ s/USAGE_\w+\([\s]*?(".*?")\s,\s".*"\s\)/$1/sg;
+			$line =~ s/USAGE_\w+\(\s*?(".*").*\)/$1/sg;
+			# Strip any empty quotes out
+			$line =~ s/"[\s]*"//sg;
+			# strip line end quotes, again
+			$line =~ s/^\s*"//;
+			$line =~ s/"\s*$//;
+
+			# Finally, print it
+			print "$line\n";
+		}
+		printf("\n\n");
+	}
+}