Month: March 2005

Using libraries

by Tom

Load and initializing the library

#include
int MathLibRef = -1;
...
// is library already loaded?
err = SysLibFind("MathLib", &MathLibRef);
if (err != 0) {
  // negative, load
  err = SysLibLoad('libr', 'MthL', &MathLibRef);
  if (err == 0) {
    err = MathLibOpen (MathLibRef, 1);
  }
}

Closing library

if (MathLibRef != -1) {
  Err err;
  UInt16 usecount;
  err = MathLibClose (MathLibRef, &usecount);
  if (usecount == 0) {
    SysLibRemove (MathLibRef);
  }
}

Preferences

by Tom

Preferences structure definition

typedef struct {
  int skeletonData;
} Prefs;
Prefs prefs;

Open preferences

void startApp() {
  Int16 prefSize = sizeof(Prefs);
  if ((PrefGetAppPreferences (AppCreator,
           1000, // pref database id
           &prefs,
           &prefSize,
            true) // saved during Hotsync
    == noPreferenceFound)
    || (prefSize != sizeof(Prefs))) {
          // default initialization, since discovered
          // Prefs was missing or old.
    prefs.skeletonData=1;
  }
}

Write preferences

void stopApp() {
  PrefSetAppPreferences (AppCreator,
        1000,  // pref database id
        1,   // version of pref database
        &prefs,
        sizeof(Prefs),
        true);  // saved during hotsync
}

Simple PHP security patch

by Tom

I’ve created (after some weird experiences with users in my hosting) small php patch (for version 4.3.10), which disables remote includes.This patch doesn’t work with Zend Optimizer enabled unfortunately :(

Download the patch there. After applying, see php.ini-dist and readme.security

example of bad code:

<?php 
  $page = $_GET['page']; 
  include ($page); 
?>

example of better code:

<?php 
  // filter all unneeded characters 
  $page = eregi_replace("[^a-z0-9_]","", $_GET['page']).".inc.php"; 
  // test if $page exists and is file 
  if (strlen($page) && @file_exists($page) && @is_file($page)) { 
    require_once ($page); 
  } 
?>