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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?
Eric Leschinski
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udaya
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5 Answers5

209

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

A J
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Benbob
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  • Are there any security implications for this? – A F Aug 12 '14 at 01:51
  • This dumps data to a php file whose filename is in the format: log-[Y-m-d H:i:s] or whatever value is set on log_date_format key configuration defined on your config file. For as long as you don't get to log/dump sensitive data, it should be pretty safe. This file is relative to an index.html page by default so obviously generated php files wouldn't be publicly accessible- but you'll never know. Make sure to have all of this precautions in place if you change the default application/logs directory. – Vincent Edward Gedaria Binua Jan 29 '15 at 02:56
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    Make your /application/logs folder writable <<< that helped me – Sergey Grechin Feb 04 '16 at 11:23
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    When I set "$config['log_threshold'] = 1;", I didn't get any logs in my /application/logs folder. However, when I set "$config['log_threshold'] = 3", a log file appeared. Hope this helps. Thank you! Peace. – masarapmabuhay Nov 10 '17 at 01:33
  • After enabling logging from the config file in the project, now you can use `error_log()` to print directly to the console. – Ahmad Yones Aug 29 '22 at 08:13
27

To simply put a line in the server's error log, use PHP's error_log() function. However, that method will not send an e-mail.

First, to trigger an error:

trigger_error("Error message here", E_USER_ERROR);

By default, this will go in the server's error log file. See the ErrorLog directive for Apache. To set your own log file:

ini_set('error_log', 'path/to/log/file');

Note that the log file you choose must already exist and be writable by the server process. The simplest way to make the file writable is to make the server user the owner of the file. (The server user may be nobody, _www, apache, or something else, depending on your OS distribution.)

To e-mail the error, you need to set up a custom error handler:

function mail_error($errno, $errstr, $errfile, $errline) {
  $message = "[Error $errno] $errstr - Error on line $errline in file $errfile";
  error_log($message); // writes the error to the log file
  mail('you@yourdomain.com', 'I have an error', $message);
}
set_error_handler('mail_error', E_ALL^E_NOTICE);

Please see the relevant PHP documentation for more info.

Mark Eirich
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4

Also make sure that you have allowed codeigniter to log the type of messages you want in a config file.

i.e $config['log_threshold'] = [log_level ranges 0-4];

Gpak
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4
In config.php add or edit the following lines to this:
------------------------------------------------------
$config['log_threshold'] = 4; // (1/2/3)
$config['log_path'] = '/home/path/to/application/logs/';

Run this command in the terminal:
----------------------------------
sudo chmod -R 777 /home/path/to/application/logs/
Charleskimani
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1

More oin regards to question part 4 How do you e-mail that error to an email address? The error_log function has email destination too. http://php.net/manual/en/function.error-log.php

Agha, here I found an example that shows a usage. Send errors message via email using error_log()

error_log($this->_errorMsg, 1, ADMIN_MAIL, "Content-Type: text/html; charset=utf8\r\nFrom: ".MAIL_ERR_FROM."\r\nTo: ".ADMIN_MAIL);
Community
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Master James
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