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.

diff --git a/docs/autodocifier.pl b/docs/autodocifier.pl
new file mode 100755 (executable)
index 0000000..2ce1edd
--- /dev/null
+++ b/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");
+       }
+}