whats the plot

i recently decided to move my tech tips microblog to identi.ca (the original copy was on jaiku), as i felt it was a little more befitting, actively developed, etc (although jaiku is now open source).

anyway… so i wanted to migrate my posts over – so i wrote a php script to do it (it assumes your jaiku is public and reads it without hassling with oauth).

<?php
$sleepTime = 5;
$jaikuSource = "http://username.jaiku.com/json";

$mode = 'identi.ca';
$baseStatusUrl = 'http://identi.ca/api/statuses/update.json';

// thanks, php-twitter
if ($mode == 'twitter'){
   $baseStatusUrl = 'http://twitter.com/statuses/update.json';
   $headers = array('Expect:', 'X-Twitter-Client: ',
      'X-Twitter-Client-Version: ','X-Twitter-Client-URL: ');
}

$ctr = 0;
$entries = array();

print "destination account username: ";
$username = trim(fgets(STDIN));
print "password: ";
system('stty -echo');
$password = trim(fgets(STDIN));
system('stty echo');
print "\n";

$done = false;
$params = '';
while (true){
   $count = 0;
   $posts = fetchUrl($jaikuSource . $params);
   $json = json_decode($posts, true);
   $stream = $json['stream'];
   $lastEntry = null;
   foreach ($stream as $entry){
      if (isset($entry['comment_id'])) continue;
      $lastEntry = $entry;
      $count++;
      $entries[$ctr++] = $entry['title'];
   }
   if ($count == 0) break;
   $lastPostTime = $lastEntry['created_at'];
   $ts = split('-', $lastPostTime);
   $hd = split('T', $ts[2]);
   $min = split('Z', $ts[4]);
   $gmtime = gmmktime($hd[1], $ts[3], $min[0], $ts[1], $hd[0], $ts[0]) - 1;
   $params = "?offset=$gmtime";
}

for ($i = $ctr-1; $i>=0; $i--){
   $params = array('status' => $entries[$i]);
   if ($i != ($ctr-1)){
      print "sleeping $sleepTime seconds\n";
      sleep($sleepTime);
   }
   twitterApiCall($baseStatusUrl, $params);
   print "updated status to: " . $entries[$i] . "\n";
}

function fetchUrl($url){
   $ch = curl_init($url);
   curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
   $resp = curl_exec($ch);
   curl_close($ch);
   return $resp;
}

function twitterApiCall($url, $args = null){
   global $username, $password, $headers;

   // thanks, php-twitter
   $ch = curl_init($url);
   if (!is_null($args)){
      curl_setopt($ch, CURLOPT_POST, true);
      curl_setopt($ch, CURLOPT_POSTFIELDS, $args);
   }
   if ((!empty($username)) && (!empty($password)))
      curl_setopt($ch, CURLOPT_USERPWD, $username . ':' . $password);
   curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
   if (!empty($headers))
      curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
   $resp = curl_exec($ch);
   $info = curl_getinfo($ch);
   curl_close($ch);
   if ($info['http_code']!=200)
      print "error - got an http code of: " . $info['http_code'] . "\n";
}

make sure you edit $baseStatusUrl and $mode as necessary. enjoy!

generally speaking, my set of mp3s is very well tagged. for my personal mp3s, i used to exclusively use easytag to tag them, and now i use a combination of easytag and amarok (which is totally awesome by the way!)

but sometimes, i have to mass edit id3tags for mp3s on the server, and i don’t have the luxury of using such gui tools for the editing. as thus, i’ve been mainly using id3v2 within some perl scripts to tag mp3s. this turns out to work great, but i also wanted to be able to add album art to the mp3s from the command line.

i couldn’t figure out how to do it using id3v2 (perhaps using the custom frames, there’s a way, but nothing extremely simple and obvious from what i was looking at). then i found the solution in the form of a id3lib-ruby, a ruby wrapper for id3lib, the same library that id3v2 is based on.

with this, everything turns out to be extremely easy -

require 'id3lib'

tag = ID3Lib::Tag.new('myfile.mp3')
cover = {
   :id => :APIC,
   :mimetype => 'image/jpeg',
   :picturetype => 3,
   :data => File.read('cover.jpg')
}

tag << cover
tag.update!

and that’s it. nice and simple. by the way, a picturetype of 3 denotes a front cover and is the default value (just learned that from a quick search). oh and the output mp3 image cover shows up fine in both linux and on itunes. beautiful!

so i was working on some code in which i needed to know whether or not it was dst for a given country and/or timezone or not. luckily, with php5.2, some sparsely documented (yet very useful) classes were introduced – a more thorough documentation can be found here.

so let’s say i want to know whether or not egypt is in dst right now or not… so first i need to know what zoneinfo file egypt uses (for egypt, it’s simple, but this trick is useful for more obscure places, like “isle of man,” for example):

cd /usr/share/zoneinfo
grep -i egypt iso*.tab        # get the iso country code for egypt

# the above command returns 'EG' - so...
grep EG zone.tab
# returns 'Africa/Cairo'

in many cases, there are many timezones that exist for a given country. in many cases, it’s obvious which file you need, but in some cases, it’s not very obvious. in those cases, i found it helpful to open the binary files and look at the very last line, in which some hint about the offset of the timezone is given.

anyway… once you have the zoneinfo file that you would use, it’s very easy to find whether or not you are in dst (well, assuming that you know what the standard, non-dst offset from utc is). for example:

$tz = new DateTimeZone('America/New_York');
$date = new DateTime();
$date->setTimezone($tz);
echo $date->;format(DATE_RFC3339) . "\n";
echo $date->getOffset()/3600 . "\n";

running this returns the time in new york, and the offset (-4). since the standard est offset is -5 hours, -4 means we’re +1 which means we are currently on dst.

so if you don’t know the standard offset, another trick that you could do is pass some parameters to the new DateTime() constructor – so for example…

$tz = new DateTimeZone('America/New_York');
$date = new DateTime('2008-12-31');
$date->setTimezone($tz);
echo $date->getOffset()/3600 . "\n";

this returns -5, which is out of dst. anyhow, you could use the above if you don’t know the default offset for a timezone for dst by passing in 2 dates – something towards the middle of the year (july-ish) and something towards the end of the year (december-ish). if the offsets are different, the place probably has dst.

also, do note that some places have things a little differently – so dst in windhoek, namibia, for example, ends in april and starts in september.

i never really used this until i ran into this article by accident, but it’s fairly cool…

so:

echo {one,two}.sh

outputs:

one.sh two.sh

this means that you can, as the article says, do something like this:

cp /etc/apache2/httpd.conf{,.bak}

to backup your apache conf. cool huh? the article has more details and such, but that’s just a summary.

today, i wanted to try out my test arabic gtk program to see if behdad’s new changes to pango magically fixed the renown arabic shaping issue [in short, it had nothing to do with it]. anyway, i discovered that i needed to install libquran, and to make a long story short, my test program, which used to work before, segfaulted. i ran gdb and valgrind only to find the segfault happening within libquran at the closing of the configuration file (noting this libquran code hasn’t been changed in 3 years now).

i looked at the source, and discovered that the file pointer was becoming null after a call to getline. i tried to see if i could reproduce this in a smaller test program, and i discovered that i indeed could -

#include <stdio.h>

int main(void){
   int n = 0;
   char* tmp;
   FILE* fp = fopen("./testfile", "r");
   getline(&tmp, &n, fp);
   printf("got a str of: %s\n", tmp);
   printf("now fp is: %s\n", (fp==NULL)? "null" : "not null");
   fclose(fp);
   free(tmp);
   return 0;
}

the program displayed the first line from testfile, but unexpectedly displayed that fp is null and segfaulted at the fclose. checking the return from getline, i see that it returns successfully (the number of characters it read).

while i got around this problem by modifying the library to do a malloc followed by an fgets, i am just confused -this library code hasn’t been touched in 3 years, it used to work before, and i just repulled it from cvs when i discovered this. so why is it broken now? the only thing that i can think of being different is that my box now runs a 64 bit version of linux, but would that break it?

any ideas?

a long time ago, when i still used to use xmms, there was this nice plugin called Repeat It! that let you say, “repeat this song between this and this times forever.”

i found myself missing that feature today… unfortunately, i don’t have xmms installed and don’t want it installed because i now like the gtk2 based mp3 players, like beep for example.

but because beep is being rewritten as bmpx, i figure rather than porting the plugin, i can just write a much simpler command line version based on the existing plugin that works with beep.

note however that this is really bad… it does very little error checking, and the sleep solution isn’t really the best solution… but its a pretty good solution for my limited uses

and in 25 lines, here it is:

#include <stdio.h>
#include <signal.h>
#include <bmp/beepctrl.h>

void got_signal(int x){
	printf("Exiting!\n"); exit(1);
}

int main(int argc, char** argv){
   int startpos, endpos;
   if (!xmms_remote_is_running(0))
      return (0*printf("\033[1mbmp is not running.\033[0m\n"))-1;

   if (argc != 3)
      return (0*printf("usage: %s start end\n", argv[0]));

   startpos = atoi(argv[1]);
   endpos = atoi(argv[2]);

   signal(SIGINT, got_signal);
   if (!xmms_remote_is_playing(0)){ xmms_remote_play(0); }

   while (1){
      xmms_remote_jump_to_time(0, startpos * 1000);
      sleep(endpos - startpos);
   }
}

to compile it, just do:

gcc `beep-config --cflags --libs` loopsegment.c -o loop

then just run beep, load up the file you want to play, and run the script passing in start and end seconds.

“Space is big. You just won’t believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.”

i finally got around to reading the hitchhiker’s guide to the galaxy. really funny book. maybe i will try to read the other books at some point.

i played around some today with ruby-gnome2 bindings. all i can say is wow. the website documentation is incredible, and you can do so much in so little code. i played around some with ruby-gtkmozembed, and in a few lines of code, you basically have a fully functional web browser.

require 'gtkmozembed'

class Main
   def initialize
      Gtk.init
      window = Gtk::Window.new
      window.resize(800, 600)
      window.title = "ahmed's google test"

      browser = Gtk::MozEmbed.new
      browser.chrome_mask = Gtk::MozEmbed::ALLCHROME
      browser.location = "http://www.google.com"
      browser.signal_connect("title"){ window.title = browser.title; }

      window << browser
      window.show_all
      window.signal_connect("destroy"){ Gtk::main_quit }
   end
end

Main.new
Gtk.main

that’s all for now.