CodeIgniter white page on cPanel

After cPanel upgrade from EasyApache3 to EasyApache4 all my CodeIgniter installations just broke on that server, returning just a white page without any error message. I spent more than one hour trying to figure out what the problem is. While testing out I noticed empty files named like these “0bce68a7a37e584ace98f0fd242a237d1662613e” or “296eed9bfb533552b0c3a9c8fdd784067eea216d”   (without any extension) started popping in my project folder. I figured out that these must be session paths so something is wrong with that.

I tried enabling php error logging but it didn’t help since it didn’t log anything since all code is right and it was working before but it just stopped after I started using EasyApache4.

So I went and enabled CodeIgniter logging that proved to be a better idea. To enable it open config.php for editing, locate

$config['log_threshold'] = 0;

And change that value to 4. That will enable internal logging system and logs will be saved in /application/logs folder. What I found out just conf

ERROR - 2016-11-29 22:36:29 --> Severity: Warning --> mkdir(): Invalid path Session_files_driver.php 117
ERROR - 2016-11-29 22:36:29 --> Severity: error --> Exception: Session: Configured save path '' is not a directory, doesn't exist or cannot be created. Session_files_driver.php 119

My session save path at config.php was set to null:

$config['sess_save_path'] = NULL;

Once I got it changed to default (alternatively you can set it up to any other folder you want locally, so you can have full control over your sessions):

$config['sess_save_path'] = sys_get_temp_dir();

everything started working again! Now this is second time I have similar quiet errors with CodeIgniter where it reports absolutely nothing – instead it just gives white screen and this can be really frustrating to debug.

 


	
			
		

Validating URL in PHP without regular expressions

Validating many things in PHP is often done using regular expressions, but since those might be complicated to understand, versions of PHP later than 5.20 have new validating mechanism built in. It’s done using filter_var function. Here are some basic examples of both old (regular expression) and new (filter_var) validation functions:

Validating URL using regular expressions:

function isValidURL($url) {
	return preg_match('|^http(s)?://[a-z0-9-]+(.[a-z0-9-]+)*(:[0-9]+)?(/.*)?$|i', $url);
}

Validating URL using filter_var:

function isValidURL($url) {
	if (filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_HOST_REQUIRED)) return true;
	else return false;
}

You will notice FILTER_VALIDATE_URL and FILTER_FLAG_HOST_REQUIRED flags in filter_var function. There are many more and here are some more real world examples

var_dump((bool) filter_var('http://www.website.com', FILTER_VALIDATE_URL, FILTER_FLAG_HOST_REQUIRED));
var_dump((bool) filter_var('http://website.com', FILTER_VALIDATE_URL, FILTER_FLAG_HOST_REQUIRED));
var_dump((bool) filter_var('www.website.com', FILTER_VALIDATE_URL, FILTER_FLAG_HOST_REQUIRED));
var_dump((bool) filter_var('website.com', FILTER_VALIDATE_URL, FILTER_FLAG_HOST_REQUIRED));

Output:

bool(true)
bool(true)
bool(true)
bool(false)

Here are some most common URL validation flags explanation

  • FILTER_FLAG_SCHEME_REQUIRED – Require the scheme (eg, http://, ftp:// etc) within the URL.
  • FILTER_FLAG_HOST_REQUIRED – Require host of the URL (eg, www.google.com)
  • FILTER_FLAG_PATH_REQUIRED – Require a path after the host of the URL. ( eg, /folder/file.ext)
  • FILTER_FLAG_QUERY_REQUIRED – Require a query at the end of the URL (eg, ?key=value)

Validating Email using regular expressions:

function isValidEmail($email) {
    return preg_match("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$^", $email);
}

Validating Email using filter_var:

function isValidEmail($email) {
	if (filter_var($email, FILTER_VALIDATE_EMAIL)) return true;
	else return false;
}

Conclusion
Validating URLs, Emails, IPs and many other things using regular expressions is history now. Code for validations using filter_var is easier to understand easier to write and looks more php geeky. You don’t have to search for “working” regular expressions for your validations… It’s all there and it’s well documented and all you need is just need to use it.
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Tags: url validation in javascript without http, php validate url

Web host is adding ?PHPSESSID to the end of all URLs

Today I a customer of mine came to me with a problem with web site that he have just moved from one host to another. And on that new host all his links on his site suddenly had ?PHPSESSID=k234j2knk… in the end. Since that is totally unusable since that site doesn’t even uses sessions and could affect his search engine rankings, he wanted it out of the way. The new host he moved that site to was shared and it doesn’t allow editing of php.ini any way so I had to make some other solution.

After failing with adding one of those on top of php files, as suggested on most pages that I found on Google:

// stop PHP from automatically embedding PHPSESSID on local URLs
ini_set('session.use_trans_sid', false);

// only use cookies (no url based sessions)
ini_set('session.use_only_cookies', true);

I suggested him to just switch hosts again, but he said he already paid up front for the whole year… and that it’s not an option… and that he wants that off his site… So, I’ve Googled some more and finally found a simple solution (that doesn’t require editing of 100’s of files in his case because of poorly programmed site). All I had to do is just put one line of code in .htaccess file and BOOM! All those nasty ?PHPSESSID were gone!

php_flag session.use_trans_sid off