--- src/perl-5.14.2/lib/perl5db.pl  2011-09-26 17:44:34.000000000 +0800
+++ perl/debug/perl5db.pl   2012-04-09 15:32:30.724616585 +0800
@@ -1480,6 +1480,24 @@
 
 =cut
 
+# Funciton which return 1 if it can locate a command, others return 0
+sub which {
+    my $return_val = 1;
+    my ( $proc, $path );
+    return 0 if ( not defined $ENV{PATH} );
+    for $proc (@_) {
+        my $found = 0;
+        for $path ( split /:/, $ENV{PATH} ) {
+            if ( -f "$path/$proc" and -X "$path/$proc" ) {
+                $found = 1;
+       last;
+            }
+        }
+        $return_val = 0 if ( !$found );
+    }
+    return $return_val;
+}
+
 # Set up the get_fork_TTY subroutine to be aliased to the proper routine.
 # Works if you're running an xterm or xterm-like window, or you're on
 # OS/2, or on Mac OS X. This may need some expansion.
@@ -1490,10 +1508,17 @@
                                                  # Expect an inetd-like server
         *get_fork_TTY = \&socket_get_fork_TTY;   # to listen to us
     }
+    elsif ( $^O eq 'linux'                     # If this is Linux
+        and defined $ENV{DISPLAY}                # and what display it's on,
+   )
+    {
+        *get_fork_TTY = \&linux_get_fork_TTY;   # use the linux version
+    }
     elsif (defined $ENV{TERM}                    # If we know what kind
                                                  # of terminal this is,
         and $ENV{TERM} eq 'xterm'                # and it's an xterm,
         and defined $ENV{DISPLAY}                # and what display it's on,
+   and which 'xterm'                        # and 'xterm' is found and executable
       )
     {
         *get_fork_TTY = \&xterm_get_fork_TTY;    # use the xterm version
@@ -6221,6 +6246,81 @@
     return '';          # Indicate that reset_IN_OUT is called
 } ## end sub os2_get_fork_TTY
 
+=head3 C<linux_get_fork_TTY>
+
+This function provides the C<get_fork_TTY> function for linux system. If a 
+program running under the debugger forks, a new window or tab is opened and
+the subsidiary debugger is directed there.
+
+The function works just like xterm_get_fork_TTY, but we use a temp file 
+instead of a special C<open()> call, because common terminal emulation
+applications, gnome-terminal and konsole, can not work in xterm way.
+
+Only works if C<terminal emulation application> is in your path and 
+C<$ENV{DISPLAY}>, etc. are properly set up.
+=cut
+sub linux_get_fork_TTY {
+    ( my $name = $0 ) =~ s,^.*[/\\],,s;
+
+    # we need store the tty name in a unique file
+    my $id_ref = \do { my $anon_scalar; };
+    "$id_ref" =~ m,.*\((.*)\),mx;
+    my $id       = $1;
+    my $tempfile = qq[perl5db-$$-$id];
+    do {
+        $tempfile .= q[-];
+        $tempfile .= int 10**12 * rand;
+    } while ( -e qq[/tmp/$tempfile] );
+    system( q[touch], qq[/tmp/$tempfile] );
+    my $title     = qq[Daughter Perl debugger $pids $name];
+    my $cmd       = qq[tty >/tmp/$tempfile;clear;sleep 10000000];
+    my %terminals = (
+        q[gnome-terminal] =>
+          qq[gnome-terminal -e 'sh -c "$cmd"' --window --title "$title" |],
+        q[konsole] => qq[konsole --title "$title" -e sh -c '$cmd' |],
+        q[xfce4-terminal] => qq[xfce4-terminal --title "$title" -e 'sh -c "$cmd"' |],
+        q[terminal] => qq[terminal --title "$title" -e 'sh -c "$cmd"' |],
+        q[lxterminal] => qq[lxterminal --title "$title" -e 'sh -c "$cmd"' |],
+   q[xterm] => qq[xterm -title "$title" -e 'sh -c "$cmd"' |],
+    );
+    my $support_terms = join qq[\n], sort keys %terminals;
+    for my $emul ( sort keys %terminals ) {
+        if ( which $emul) {
+            open XT, qq[$terminals{$emul}];
+
+            # Get the output from 'tty' and clean it up a little.
+            # We need wait a while before tty command outputs result to $tempfile
+            sleep 1 while ( -z qq[/tmp/$tempfile] );
+            open TEMP_HANDLE, qq[/tmp/$tempfile];
+            unlink qq[/tmp/$tempfile];
+            my $tty = <TEMP_HANDLE>;
+            close TEMP_HANDLE;
+            chomp $tty;
+            $pidprompt = '';    # Shown anyway in titlebar
+                 # We need $term defined or we can not switch to the newly
+                 # created a new terminal window or tab
+
+            if ( $tty ne '' && !defined $term ) {
+                require Term::ReadLine;
+                if ( !$rl ) {
+                    $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT );
+                }
+                else {
+                    $term = Term::ReadLine->new( 'perldb', $IN, $OUT );
+                }
+            }
+
+            # There's our new TTY.
+            return $tty;
+        }
+    }
+    print <<EOF;
+Now on linux system, we only support terminals as follows:
+$support_terms
+EOF
+    return undef;
+} ## end sub linux_get_fork_TTY
+
 =head3 C<macosx_get_fork_TTY>
 
 The Mac OS X version uses AppleScript to tell Terminal.app to create
@@ -6357,7 +6457,8 @@
 EOP
         print_help(<<EOP);
   I know how to switch the output to a different window in xterms, OS/2
-  consoles, and Mac OS X Terminal.app only.  For a manual switch, put the name
+  consoles, Mac OS X Terminal.app, and some linux common graphical terminal
+  emulation applications only. For a manual switch, put the name
   of the created I<TTY> in B<\$DB::fork_TTY>, or define a function
   B<DB::get_fork_TTY()> returning this.