added listArduinos.pl to show a way to do it on Mac OS X

listArduinos.pl

@@ -0,0 +1,82 @@
+#!/usr/bin/perl -w
+#
+# listArduinos.pl -- look for Arduino (UNOs) and print out useful information
+#                    about them like VID/PID and serial port name
+#                    For Mac OS X only at the moment
+#
+# 
+# http://github.com/todbot/usbSearch/
+#
+# 2012, Tod E. Kurt, http://todbot.com/blog/
+#
+#
+
+my $debug = 0;
+
+my $output = `/usr/sbin/system_profiler SPUSBDataType`;
+
+my @lines = split "\n", $output;
+
+
+print "Finding Arduino UNOs...\n";
+
+#
+sub make_portname {
+    my ($location_id) = @_;
+    my $base = substr( $location_id, 2,4 );
+    return "/dev/tty.usbmodem" . $base . "1";            
+}
+
+my $look_state = 0;
+my $arduinos = {};
+my $arduino = {};
+foreach my $line (@lines) {
+    chomp($line);
+    print "line: '$line'\n" if( $debug>1 );
+    $line =~ s/\s+/ /;
+    if( $look_state == 0 ) { 
+        if( $line =~ /Arduino Uno/ ) {
+            $look_state = 1;
+        }
+    }
+    elsif( $look_state == 1 ) { 
+        if( $line =~ /^$/ ) {
+            $look_state = 2;
+        }
+    }
+    elsif( $look_state == 2 ) {
+        if( $line =~ /Serial Number: (.+)$/ ) {
+            $arduino->{'serial_num'} = $1;
+        }
+        if( $line =~ /Location ID: (.+)$/ ) { 
+            $arduino->{'location_id'} = $1;
+        }
+        if( $line =~ /Product ID: (.+)$/ ) { 
+            $arduino->{'pid'} = $1;
+        }
+        if( $line =~ /Vendor ID: (.+)$/ ) { 
+            $arduino->{'vid'} = $1;
+        }
+        if( $line =~ /^$/ ) {
+            $look_state = 0;
+            $arduino->{'portname'} = make_portname($arduino->{'location_id'});
+            $arduinos->{ $arduino->{'serial_num'} } = $arduino;
+            $arduino = {}; # reset
+        }
+    }
+}
+
+my @serial_nums = keys %$arduinos;
+my $count = scalar @serial_nums;
+foreach my $serial (@serial_nums) { 
+    my $ard = $arduinos->{$serial};
+    printf("%s - %s/%s - %s\n", 
+           $ard->{'portname'},
+           $ard->{'vid'}, 
+           $ard->{'pid'},
+           $ard->{'serial_num'}
+        );
+}
+
+print "Found ". $count ." Arduino UNO". (($count==1)?"\n":"s\n");
+