$ time python mandel.py > \dev\null
real	0m0.051s
user	0m0.036s
sys	0m0.010s
$ time perl mandel.pl > \dev\null
real	0m3.518s
user	0m3.463s
sys	0m0.029s

You can find the code here.

This script works well for zooms, as long as you stay below a few thousand iterations. The following picture was generated with x=-1.1887204, y=-0.3032472, width=0.01 and 150 iterations.

After the jump, I’ll give you the code and explain how it all works.

How it Works:

The code from ~/.conkyrc that makes this calendar is simple:

${color orange}CALENDAR ${hr 2}$color
${execpi 60 DJS=`date +%_d`; cal | sed s/"$DJS"'\b'/'${color orange}'"$DJS"'$color'/}

This is a somewhat complicated expression, but what it does is fairly simple. The first line simply draws the title for the section, and it’s the second line that does the magic. Let me break it down and explain it.

${execpi 60

This command tells Conky to execute the next argument every 60 seconds, and, importantly, parse the output of that argument. This way, when we put in commands that change the text color, Conky will obey them instead of printing them.

DJS=`date +%_d`;

DJS (which stands for “date” followed by my initials) is a temporary variable that holds the current day of the month, padded with a leading space, if necessary (so that we’ll catch the first of the month, not every 1 in the calendar, for example).

cal |

cal simply prints out a simple calendar, and the pipe feeds that output through to the next commmand:

sed s/"$DJS"'\b'/'${color orange}'"$DJS"'$color'/

This is one big mess of a command, but the main body is a regex that sed takes as an argument. The regex searches for the string “$DJS”‘\b’, which means the contents of the variable DJS (which we set earlier) followed by a word boundary – a change from printable characters to white space. This means that it will find the current date (one or two digits) but won’t find the 3 of the 30th on the third of the month. It also means that it will work correctly if the current date is on the far left or right column of the calendar.

The second half of the regex simply wraps what it found the first time around in a couple of Conky commands that change to color to orange, and then back to what it was before.

Lastly, the closing bracket (}) at the end of the line closes out the opening one that is required for all Conky commands with arguments.

Now go forth and cover your desktop in beautiful calendars.

Just Another Perl Hacker

I figured that it was about time in my hacking career (read: I was bored enough) that I should make a japh script. After a couple attempts I came up with this:

#!/usr/bin/perl
while(<DATA>){
 	for (map{ord($_)-33}split ''){
		$__++;
		$_||(print(chr($__+19))&&($__=0));
	}
}
 
print "\n";
 
__END__
                   /|                        |\
      !            ; :                        : :
                  | Y,                      ,P |
     !             |  Yb.        __        ,dP  |
                  l\  YMMb,_ _,/  \,_ _,dMMP  /f
  !                 j;  `YMMP'  `--'  `YMMP'  ;j
                   : \   YP`-._    _.-'YP   / ;
  !            !      \ `\,  _,\_    _/,_  ,/' /
                     `,_,   \`o>  <o'/   ,_,!'
                         `\            /'
                           |  _    _  |
      !                     / 88b  d88 \
                           \ `8P  Y8' /``-.
             !               `\,    ,/      \
                             _`----'        \
                  !        _.'/ '          `, \
                        .'_,'_..._          \ ;
       !               .',/.dMMMMMMb. |      /  \
                    .'./.MMMMMMMMMMM ; !    /    ;
                   / /.MMMMMMMMMMMMM/     /     ;
                  | ;dMMMMMMMMMMM!P/'   ,/'   !    ;
                  |/dMMMMMMMMMP'     .'          |
   !               ;dMMMMMMMMM|     _/            |
                 ;dMMMMMMMMMMb_|_!| /;            ;\,
                 dMMMMMMMMMMMM`M`M`;.---..      '   `\,
                :M!MMMMMMMMMMMMMMMP/'     `\            \
               /|MMMMMMMMMMMMMMP/          \    _!_      `.
  !            / |MMMMMMMMMMMMMM|            |.-'  `-._    \         .'\
             ;!  ;MMMMMMMMMMMMMM|            :         `-._ `-.     /  _\
             |   ;!MMMMMMMMMMMMM;            |             `-. `-.._.'/
              \   `\YMMMMM!MMMP/'\           |                `~~----'
               `-._, ``YMMMP'_.-'\         ! ;_
                 |      /         `-.,_./     7
                _/    `\,    !        /      _/
             ,-' ,  ,   /         _.'      /
            (_(_(__(__.'       !,-'        /
                              (__(__(_(_/'

Download.

I’ll let you go ahead and figure it out on your own. It’s not super-hard, but it’s fun.

Mandelbrot

In another fit of boredom I decided that it was finally time to create a mandelbrot set renderer. I originally tried to make one of these in basic, long before I had the math to do so. I was proud that I got the real axis to render, and figured it was time to complexify it. To keep things simple I decided to make it render an ASCII-art version of the set that would fit in a terminal window. The output looks like this:

                        ...............................:::::oo@@@@o::::..........
                      ...............................::::::O@@@@@@@@o:::::.......
                     .............................::::::::oO@@@@@@@@o::::::::....
                   ...........................::::OOO8ooO@O88@@@@@@8@O8o::::Oo:..
                  .......................:::::::::o8@@@@@@@@@@@@@@@@@@@@OO@@@@::.
                 ...................:::::::::::::oOO@@@@@@@@@@@@@@@@@@@@@@@@@o:::
                ................:::::::::::::::o@@@@@@@@@@@@@@@@@@@@@@@@@@@@Oo:::
               ..............::::@oo::oOoo:::ooo@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@8o:
               ...........:::::::oO@@@O@@8@OooO8@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@O::
              ..........:::::::::oO@@@@@@@@@@88@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@::
              ........:::::::8ooO8@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@o::
              .:::::::::::::oO@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@o:::
              @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Oo::::
              .:::::::::::::oO@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@o:::
              ........:::::::8ooO8@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@o::
              ..........:::::::::oO@@@@@@@@@@88@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@::
               ...........:::::::oO@@@O@@8@OooO8@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@O::
               ..............::::@oo::oOoo:::ooo@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@8o:
                ................:::::::::::::::o@@@@@@@@@@@@@@@@@@@@@@@@@@@@Oo:::
                 ...................:::::::::::::oOO@@@@@@@@@@@@@@@@@@@@@@@@@o:::
                  .......................:::::::::o8@@@@@@@@@@@@@@@@@@@@OO@@@@::.
                   ...........................::::OOO8ooO@O88@@@@@@8@O8o::::Oo:..
                     .............................::::::::oO@@@@@@@@o::::::::....
                      ...............................::::::O@@@@@@@@o:::::.......
                        ...............................:::::oo@@@@o::::..........

The code’s far from polished and not what I like to publish, but it’s a fun thing to look at and offers you some neat abilities to poke things around and fix some pesky problems that just need clear thinking applied to them. It’s available here.

When it showed up, some quick software probing revealed that it houses a usb to serial adaptor (a Prolific PL-2303, which I’ll get to in a bit) and a gps module that’s configured to send NMEA strings through the virtual serial port. This sort of information is compatible with a host of software, but most of it is commericial, and only available at a considerable price.

Luckily, there’s a wonderful open source project called gpsd which provides support for a wide raft of devices and protocols, and talks to an even wider assortment of software. Primarily, I wanted to be able to get my gps to talk to the network scanner Kismac, and Randall Munroe’s cyborg.py script. Both of these were built to take information from gpsd, so I was in business. However, gpsd, which is designed to play nicely with Linux, takes some coaxing under OS X. This is meant to describe how I got it all running.

I. Hardware driver

Because the gps relies on a usb-to-serial chip to talk to the computer, it needs a driver that will emulate a serial port. The chip in my gps revealed itself as a Prolific PL-2303, a common chip that I’d had previous dealings with, and so had a driver for. This enabled me to see a serial device on my system and read raw data from it:

sethjust$ ls /dev/cu.*
/dev/cu.Bluetooth-Modem		/dev/cu.Bluetooth-PDA-Sync	/dev/cu.PL2303-0000101D
sethjust$ stty -f /dev/cu.usbserial ispeed 4800 && cat </dev/cu.usbserial
,,,3.6,2.2,2.8*3E
$GPRMC,060645.994,A,4537.5498,N,12259.8000,W,000.0,327.4,120109,,,A*70
$GPVTG,327.4,T,,M,000.0,N,000.0,K,A*0F
$GPGGA,060646.994,4537.5498,N,12259.8000,W,1,06,2.2,137.3,M,-21.5,M,,0000*63
$GPGSA,A,3,23,25,13,04,32,20,,,,,,,3.^C

This driver also played nicely with some of the commericial software demos I’d downloaded, but oddly enough it didn’t work with gpsd. Eventually, after some debugging and consulting with one of gpsd’s developers via IRC, I replaced the driver I had (an open source replacement for proprietary driver) with the driver from Prolific’s website. Supposedly the open-source PL-2303 driver doesn’t play nicely with gpsd, and so they recommend using Prolific’s.

II. gpsd and gpsdrive

The gpsd package comes with several useful support utilities, but one that it doesn’t include is gpsdrive, a wonderful program that supports mapping and live data from gps. Getting both running under OS X is a little difficult, but I found a great document here that explains the process. A little has changed, so here’s how I got it working (though I never did get xgps or xgpsspeed to compile…):
1) Install fink if you haven’t already.
2) Install gpsdrive through fink:

$ fink install gpsdrive

3) Rename /sw/bin/gpsd to gpsd-1.06b:

$ sudo mv /sw/bin/gpsd /sw/bin/gpsd-1.06b

4) Download the latest source for gpsd. I used the latest RC for their upcoming 2.38 release and have had no problems.
5) In the gpsd source directory, run ./configure with whatever options you’d like. The earlier document had some suggestions on getting it to see X11 libraries, but I haven’t been able to make them work. I ended up using

$ ./configure --bindir=/usr/local/bin -without-x

6) Compile the software by typing “make”. You can then either install it with “sudo make install” or test it before installing:

$ ./gpsd -n /dev/cu.usbserial
$ ./cgps

In my case /dev/cu.usbserial is the device representing the PL-2303. You should replace this with your own.

Running cgps should show a live summary of the information that gpsd is getting, along with a running log of the raw data coming from the gps. You can also test gpsd by telnetting to localhost:2947, typing w and hitting enter. You should see NMEA strings from the gps.

III. Kismac and cyborg.py

The original reason that I embarked on this gps adventure was to use two programs: Kismac and Randall Munroe’s cyborg.py. Kismac is easy to get running with gpsd – once you have gpsd running (e.g. gpsd -n /dev/cu.usbserial), open Kismac and set it to use gpsd for map coordinates. It should display your location on the map screen, and associate coordinates with APs.

cyborg.py is a little harder to get running. It’s dirty (though entirely functional) code that isn’t fully mac compatible. Notably, it uses two programs (flite and figlet) that are iffy under OS X. I patched that up, replacing flite with OS X’s built-in “say” command, and commenting out the figlet bits (which display large text) in favor of the terminal output the script gives. The modified script works beautifully, although I didn’t clean up the code at all. You can get it here.

IV. Links

• gpsd
• gpsdrive
• Kismac
• Randall Munroe’s cyborg.py
• Post by Hashim on the gpsdrive mailing list
• Prolific PL-2303 and driver
• PL-2303 Alternative Driver
• Getting maps in gpsdrive
• My gps

To start, installing Finance::Quote is a breeze. As long as you have CPAN installed, just type at the command line:

$perl -MCPAN -e shell
>install Finance::Quote

From there it’s easy to get start, it’s just a matter of importing the module and creating and instance. This means the beginning of our script will look like:
[sourcecode language='php']#!/usr/bin/perl -w
use strict;

# import module
use Finance::Quote;
# create object
my $q = Finance::Quote->new();[/sourcecode]
The instance that we created has one main method: fetch(). It takes a list of arguments, with the first being a the exchange to look for quotes on, and the remaining being a list or array of ticker symbols. The Finance::Quote documentation provides the following list of valid exchanges:

australia           Australan Stock Exchange
dwsfunds            Deutsche Bank Gruppe funds
fidelity            Fidelity Investments
tiaacref            TIAA-CREF
troweprice          T. Rowe Price
europe              European Markets
canada              Canadian Markets
usa                 USA Markets
nyse                New York Stock Exchange
nasdaq              NASDAQ
uk_unit_trusts      UK Unit Trusts
vanguard            Vanguard Investments
vwd                 Vereinigte Wirtschaftsdienste GmbH

For the purposes of this script, I’m going to stick to “usa” because it covers both NYSE and NASDAQ, and those are the stocks I’m interested in.
Fetch() returns a two-dimensional hash of results. The first index (or dimension) is the ticker symbol of the stock and the second is the label for the specific piece of information. For now, the labels that we’re interested are the name of the company (‘name’) and the price (‘price’). A full listing of labels is available in the Finance::Quote documentation.
Using this information we can now build a simple script to fetch a stock quote:
[sourcecode language='php']#!/usr/bin/perl -w
use strict;

# import module
use Finance::Quote;

# create object
my $q = Finance::Quote->new();

# retrieve stock quote
my %data = $q->fetch(‘usa’, ‘GOOG’);

# print price
print $data{‘GOOG’, ‘price’} . “n”;[/sourcecode]
This script, although it does what it’s supposed to, isn’t very pretty. By adding a little code to read ticker symbols from the command line we can check on multiple stocks at the same time, as well as remove the need to hard-code the ticker symbols. We can also make it produce much prettier results by adding more information about the company and add some basic error checking, which yields the following script:
[sourcecode language='php']#!/usr/bin/perl -w
use strict;

# import module
use Finance::Quote;

# create object
my $q = Finance::Quote->new();

#print usage information
if (length(@ARGV) == 0) {
print “Usage: $0 ticker1, ticker2, … , tickerNn”;
exit;
}

# get stock symbols from the command line and
# format them correctly (uppercase)
for (@ARGV){
$_ = uc();
}

# retrieve stock quote
my %data = $q->fetch(‘usa’, @ARGV);

# print result for each stock
for (@ARGV){
if ($data{$_, ’success’}) { # if getting the quote succeeded
my $name = $data{$_, ‘name’}; # build a report
my $price = $data{$_, ‘price’};
my $message = ”;
$message .= $name . ‘ (‘ . $_ . ‘)’;
$message .= ‘ ‘ x(25 – length($message));
$message .= “$$pricen”;
print $message;
}
else { print “Failed to retrieve quote for $_: $data{$_, ‘errormsg’}n”; }
}[/sourcecode]
This is very simple, but it does its job well:

$ quote goog msft aapl dell java
GOOGLE (GOOG)            $352.32
MICROSOFT CP (MSFT)      $22.32
APPLE INC (AAPL)         $98.23
DELL INC (DELL)          $11.99
SUN MICROSYSTEMS (JAVA)  $4.54

Download the script here