Null Disquisition

Lots of talk about nothing
 

Getting to it

Dis·qui·si·tion, n. - A formal discourse on a subject, often in writing. Started seriously getting the ball rolling on my thesis this week, outlines and everything. I found a really great app for writing called Scrivener (non free, OS X only). Notice that I said writing, not publishing. For my purposes, it does rather poorly as a publishing platform, but I have that end of things worked out rather well (

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 represent!). 1000 words in the first day. Granted, they are the easy words (background and lit review), but hopefully I can keep up a moderate pace so I can defend this summer. Once I start finishing sections and moving my draft into LaTeX, I'll start publishing them somewhere here. Probably not in this blog, but maybe a directory for a Latex2HTML dump. In other news, we got a Nikon d80. All the recent pics in my Flickr stream are taken with it (minimal post-processing). It's nice to be writing again.

Filed under  //   School   php   thesis  
Posted February 19, 2009
 

CodeIgniter Session id

Just a quick blurb. I had a problem with CodeIgniter regenerating the session id all willy-nilly. Here's a snip from the config. 

$config['sess_cookie_name'] = 'ci_session';
$config['sess_expiration'] = 54000;
$config['sess_encrypt_cookie'] = TRUE;
$config['sess_use_database'] = TRUE;
$config['sess_table_name'] = 'sessions';
$config['sess_match_ip'] = TRUE;
$config['sess_match_useragent']  = TRUE;
$config['sess_time_to_update'] = 300;
Turns out, CodeIgniter will regenerate the session id every time it updates the session table in the database. So, by default the session id gets regenerated every 5 mins (300 seconds). Instead of changing the sess_time_to_update value, I dug around in the code for a bit. Here's the culprit. (In basedir/system/libraries/Session.php) 
$old_sessid = $this->userdata['session_id'];
$new_sessid = "";
while (strlen($new_sessid) < 32)
    $new_sessid .= mt_rand(0,mt_getrandmax());
$new_sessid = md5(uniqid($new_sessid,True));
Talk about entropy... Quick hack: comment out these lines and set $new_sessid = $this->userdata['session_id']; -David

Filed under  //   ci   codeigniter   hacks   php  
Posted June 23, 2008