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PHP Error Handling

Look at the guide
   http://php.net/manual/en/book.errorfunc.php

Development Server Setup...

  I have enabled the following in the "php.ini" file for the system
  PHP configuration.

    display_errors = On
    display_startup_errors = On
    log_errors = Off

  This means PHP script should now report errors with the HTML output.

  This is good for development, though it is not really recommended for
  production environments.

  The "Examples" section in the above also contains a larger error handler
  sub-routine. And outputting program errors to the error log using the
  error_log() function.


Redirect errors to a log file

  However these settings and others given in the above manual, can be set
  in user scripts to specify the filename into which errors should be
  logged using the  ini_set() function.

  Thus something like this is recommended to be added to any and all
  user PHP scripts, to define where run-time errors should be sent
  for that script.

      ini_set('error_log', '/tmp/script_errors.log');
      ini_set('log_errors', 'On');
      ini_set('display_errors', 'Off');

  Note the file "script_errors.log" may need a full path, and should be
  writable by the Apache web server user.
  That is it should exist with permissions   701   (writable by others)

  You also should think about preventing that file 'growing forever'
  over long periods of time.  For example truncating or rolling the errors log
  appropriatally at the start of each run.

  This error log redirection will not help with compile-time errors, but the
  previous system setup however will at least report such problems, until the
  users scripts own ini_set() commands can be executed.


Redirect to Display

  This is similar to the above but adds some 
  but you need to provide some error wrapping

    ini_set('log_errors', 'Off');
    ini_set('display_errors', 'On');
    ini_set('error_prepend_string', "\n<H1>Error</H2><PRE>\n");
    ini_set('error_append_string', "\n</PRE>\n");

    header("Content-type: text/html");
    ...

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