diff -Nurp rxvt-unicode-8.3/src/command.C rxvt-unicode/src/command.C
--- rxvt-unicode-8.3/src/command.C	2007-08-01 19:32:51.000000000 +0200
+++ rxvt-unicode/src/command.C	2007-08-17 18:13:56.000000000 +0200
@@ -1227,6 +1227,7 @@ rxvt_term::pty_fill ()
 
   if (r > 0)
     {
+      HOOK_INVOKE ((this, HOOK_TT_READ, DT_STR_LEN, cmdbuf_endp, r, DT_END));
       cmdbuf_endp += r;
       return true;
     }
diff -Nurp rxvt-unicode-8.3/src/hookinc.h rxvt-unicode/src/hookinc.h
--- rxvt-unicode-8.3/src/hookinc.h	2007-06-26 01:47:14.000000000 +0200
+++ rxvt-unicode/src/hookinc.h	2007-08-17 18:14:50.000000000 +0200
@@ -21,6 +21,7 @@
   def (OSC_SEQ)
   def (OSC_SEQ_PERL)
   def (TT_WRITE)
+  def (TT_READ)
 
   def (REFRESH_BEGIN)
   def (REFRESH_END)
diff -Nurp rxvt-unicode-8.3/src/perl/mvgdbg rxvt-unicode/src/perl/mvgdbg
--- rxvt-unicode-8.3/src/perl/mvgdbg	1970-01-01 01:00:00.000000000 +0100
+++ rxvt-unicode/src/perl/mvgdbg	2007-08-17 21:17:20.000000000 +0200
@@ -0,0 +1,34 @@
+#! perl
+
+sub on_tt_read {
+  my ($term, $octets) = @_;
+  my $handle = $term->{'mvgdbg:handle'};
+  $octets =~ s/([^ -\[\]-~])/sprintf('\x%02x', ord($1))/eg;
+  print $handle "> $octets\n";
+  return ();
+}
+
+sub on_tt_write {
+  my ($term, $octets) = @_;
+  my $handle = $term->{'mvgdbg:handle'};
+  $octets =~ s/([^ -\[\]-~])/sprintf('\x%02x', ord($1))/eg;
+  print $handle "\t\t< $octets\n";
+  return ();
+}
+
+sub on_start {
+  my ($term) = @_;
+  my $handle;
+  open $handle, ">", "/tmp/mvgdbg.txt"
+    or urxvt::warn "Error opening debug file: $?";
+  $term->{'mvgdbg:handle'} = $handle;
+  return ();
+}
+
+sub on_destroy {
+  my ($term) = @_;
+  my $handle = $term->{'mvgdbg:handle'};
+  close $handle
+    or urxvt::warn "Error opening debug file: $?";
+  return ();
+}