June 2nd, 2009 by adam
(aka “why do my include/require/include_once/require_once files not work / seem NOT to be included, even though they are?”)
PHP has a mechanism for including files inside each other. The architects of PHP didn’t really think much about what they were doing with a lot of the core language features (witness the foolishness over Register Globals), and file import/include/require is a classic example.
This is one of the most fundamental features of the language, and it’s screwed up. It “seems” to work, so long as you write simplistic enough / small enough apps. The bigger your app, the more likely it is you’ll discover how poor this part of the language is.
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April 5th, 2009 by adam
I’m just finishing up a quick PHP project at the moment, which allows anyone to register an account – so as the final step before launching it, I needed to add some form of CAPTCHA system. I tried a couple of 3rd party ones and source code ones and none quite worked for me. This post gives full source for a simple user-friendly photo-based CAPTCHA in PHP. Use at your own risk – but it’s short and easy to integrate.
NB: this was more a quick-and-dirty practice exercise than a serious attempt at a CAPTCHA. I don’t believe in CAPTCHAs, generally – but if you ARE going to use them, it’s best to have a lot of them in the wild, so it’s harder for crackers to do “crack once, spam everywhere”. See the section at the bottom for links to suggestions for other people’s CAPTCHAs that I reckon would be better for production use if you can get them to work :).
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April 4th, 2009 by adam
Sadly, the code snippets on MySQL’s main website for PHP are mostly untested and buggy (try running them – half of them don’t execute because of silly mistakes).
After much trial and error, here’s one that *actually works*:
// Missing feature (?) from MySQL: find the list of valid ENUM values for a given ENUM
// (actually, returns all the value-arrays for ALL the enum fields in a given table, by name)
// ---------------------------------------------------------
function fetchEnumValuesForTable( $tablename )
{
global $db; // assuming you're using PEAR:DB here, and throughout (I use it, or MDB, exclusively)
$enumresult = $db->query("SHOW COLUMNS FROM $tablename");
// Makes arrays out of all ENUM type fields.
// Uses the field names as array names and skips non-ENUM fields
while( $enumrow = $enumresult->fetchRow() )
{
extract($enumrow);
if (substr($Type, 0, 4) != 'enum') continue;
$Type = str_replace('enum', 'array', $Type);
// Add to array
eval( '$tmp = '."$Type;" ); // I'm not sure why, but I had to do this
// intermediate step to get it to work
$results[$Field] = $tmp;
}
return $results; // returns an array mapping each enum's "column name"
// to "array of elements valid fo that ENUM"
}
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