How to do error logging in CodeIgniter (PHP)

Question

I want error logging in PHP CodeIgniter. How do I enable error logging?

I have some questions:

1. What are all the steps to log an error?
2. How is an error log file created?
3. How to push the error message into log file (whenever an error occurs)?
4. How do you e-mail that error to an email address?

Answer 1

CodeIgniter has some error logging functions built in.

• Make your /application/logs folder writable
• In /application/config/config.php set
  $config['log_threshold'] = 1;
  or use a higher number, depending on how much detail you want in your logs
• Use log_message('error', 'Some variable did not contain a value.');
• To send an email you need to extend the core CI_Exceptions class method log_exceptions(). You can do this yourself or use this. More info on extending the core here

See http://www.codeigniter.com/user_guide/general/errors.html