error_log in the same directory as included files?

Question

I've researched different methods and directives including:

• auto_prepend_file
• .user.ini files
• getcwd()
• debug_backtrace()

And I can't seem to find a way to change the path of the error_log to log in the same path as the file being included/required.

For example, say index.php has the line:

include('subdir/file.php');

If subdir/file.php has a syntax error, forcing php to create subdir/error_log, rather than the default behavior of creating error_log in the same path as index.php, auto_prepend_file suffers from this same limitation as it prepends the specified file before the first script called, rather than each file included.

I've looked around and can't seem to find a legitimate way to do this. I understand the implications of performance overhead by doing this, and plan to only use it for development purposes. I believe this can help isolate errors rather than using stack traces such as debug_backtrace(), as I can use a terminal script to show the last error logs by last modified, and find the offending files much quicker than reading through a massive error log.

My goal is ultimately not to have these files appear at all, obviously, as debugging already existing sites and having to go through a 10GB error logs or tail/multitailing it can be somewhat cumbersome. I'm trying to devise this method so errors can be isolated by path. Any suggestions?

Answer 1

Based on hakre's suggestions above, I've created this script, to be included at the top of any php script:

(also here is a gist I made of this file if you wish to fork/download it: view on github )

<?
function custom_error_debug($errno, $errstr, $errfile, $errline, $errvars) {
  $message = "";
  $message .= "[ " . date('Y-m-d h-i-s') . " ] Error: [$errno] $errstr on line $errline of $errfile ";

  //Dump all info to browser!
  //WARNING: Leave this commented except for extreme cases where you need to see all variables in use!
  //Using this will cause excessive processing time, and RAM. Use only as needed!
  /*if (!empty($errvars)) {
     echo $message . PHP_EOL . "Variables in use: <pre>";print_r($errvars); echo "</pre>";
     //WARNING: not ending execution here may cause the browser to overload on larger frameworks, comment out at your own risk!
     die();
  }*/

  //get the directory of the offending file, put a log in that path, and separate them by end of line, append to file
  file_put_contents ( dirname($errfile) . "/php_errors.log", $message . PHP_EOL, FILE_APPEND );

  //Dump all variables to file as well, (MAY CAUSE LARGE FILES, read above)
  //file_put_contents ( dirname($errfile) . "/php_errors.log", $errvars . PHP_EOL, FILE_APPEND );

  //Optionally end script execution
  //die();
}
set_error_handler('custom_error_debug');
?>