Prolog Mod

Prolog Mod
Summary	Adds PHP Rotating Logs to TNG site
Validation
Mod Updated	8 Jan 2025
Download link	version 15.0.0.22.zip TNG 15.0 version 14.0.0.20.zip TNG 14.0 version 12.0.0.9.zip TNG 12.0
Download stats	view statistics
Author(s)	Rick Bisbee
Homepage	Bisbee Family Connection
Mod Support	Support for Prolog_Mod
Contact Developer	As above
Latest Mod	15.0.0.22
Min TNG V	15.0
Max TNG V	15.0+
Files modified
Related Mods
Notes

Prolog (PHP Rotating Log) Introduction

Prolog is a utility for TNG testers, mod developers and anyone who wants to monitor their websites for PHP or user issues. It is an extension of the Show PHP Errors mod created by Roger Mitchell (decd) and provides nine selectable levels of error logging from Errors only to all errors, warnings, notices and deprecations. An important feature is that fatal errors displayed to the screen are generic and never reveal server information that a hacker may be looking for. The actual error can be found in the error log using the same timestamp shown on the screen.

Important Note for TNGv14 Users

Prolog was updated for TNGv14. In Previous versions, Prolog was initialized in subroot.php. Starting with TNGv14, Prolog v14 is initialized in begin.php. This change makes it very important that you completely uninstall any previous versions you may have tried in TNGv14, before installing Prolog v14. Neglecting to do this may leave unwanted code in TNG files that will result in TNG errors and even site failure.

Prolog v14 will fail with errors if any components of previous versions have not been uninstalled.

Error Log Location

You must set the php.ini error_log directive with the full server path to the PHP error log for the site. Error logs can be located above the public_html for greater security (recommended.) In a local WAMP server you can edit it directly into the WAMPS php.ini file. On a shared hosting server you may be able to add a php.ini file to your root directory with just this directive to override the master php.ini. Some hosts allow a user.ini to serve the same purpose. See PHP error log for additional information on setting up error logs. The directive will look something like this (note the absolute server path):

error_log = /home/mysite/mylogs/php_error.log

OR FOR A WAMPS where wamps is your server folder name

error_log = D:/wamps/logs/php_error.log

Log Rotation

Both Prolog and the PHP system will log errors to the PHP file. At the close of each GMT day Prolog will archive the PHP log to a dated backup and start the PHP log over again. After the first day no single log will contain more that one day's errors. That keeps all of them relatively small and manageable.

Prolog modifies subroot.php to add logging to all TNG pages. Scripts that work independently of TNG will not be logged by this mod; however, those errors will be logged by the system in the same PHP log.

That said, if you do want to Prolog independent scripts, you can include prolog_conf.php at the top of a primary (as opposed to an included) script and as long as the mod remains installed, errors will be logged in the same way as TNG scripts to protect fatal errors from revealing server information.

if(file_exists('prolog_conf.php'))
   require_once 'prolog_conf.php';

How Prolog Works

Prolog has two main files:

1. prolog_conf.php creates the log files and directs the logging
2. prolog.php displays and manages rotating logs from the Admin screen.

Prolog adds a log access page link in the TNG Admin management area and features the following:

• Rotating error logs are created daily to prevent them becoming too large to manage;
• The php.ini error log collects all of today's errors;
• Errors from previous days may be found in the dated archive logs;
• Archived logs and error entries are timestamped using the timezone set in php.ini;
• A clock is provided for admin perspective on timestamps;
• Mod Edit Option to select error level for logging;
• Mod Edit Option to set number of daily logs to keep before auto-deleting the oldest;
• Logs selectable from drop down list (see screen shot);
• Logged items are listed from most recent to oldest for admin convenience;
• A Filter is provided to limit viewing of logged errors to only items of interest;
• Language support included in mod folder for easier maintenance;
• A fatal shutdown handler.

Shutdown Handler

The shutdown handler is for errors that might not otherwise be logged because the system shuts down before processing them. Some, but not all servers are able to log fatal errors before shutting down, so there may be double entries in the logs -- but there will always be at least one if it occurs.

Fatal errors are very useful for revealing deliberate attacks that often result in displaying server information that attackers hope to exploit. While Prolog records them for the administrator, all the attacker sees is this, for example, after attempting to access a forbidden script:

[20-02-24 18:34:02] Something went wrong. Please report the error or come back later.

The exact time can be used to compare with the logs, should a legitimate user choose to report it. Compare the actual log entry with the displayed message above:

[24-Feb-2020 18:34:02 America/Phoenix] PRO Fatal error: File access violation in fgw/fgw_setup.php on line 26 

This was probably a hack attempt. Both the displayed and logged errors were triggered by fgw_setup.php using the following code:

// ONLY ADMINISTRATOR GETS ACCESS TO THE SETUP PAGE
if( empty( $superuser ) ) {
	trigger_error( $admtext['wse_access'], E_USER_ERROR );
   die();
}

Language Support

The mod support folder contains support for Czech, English, French, German, Spanish and Swedish. You can modify the files right in the support folder to change the translations. You can add new folders with other languages if you like. If you make changes or additions I will be happy to add them to the distribution package for others to use as well. Just email them to me or use the mod support link on the Prolog_Mod TNGWiki page.

Using the PHP and System Logs

In your php.ini set the logfile, for example:

error_log = D:/wampsdir/mylogs/php_error.php

Prolog will detect the file and use it to log errors.

If you want to view Apache system logs in your WAMPS, in your WAMPS httpd.conf file set up a VirtualHost something like this.

<VirtualHost *:80>
	ErrorDocument 404 /errdocs/_err404.php
	ErrorDocument 403 /errdocs/_err403.php
	ErrorLog D:/wampsdir/mylogs/server_error.log
</VirtualHost>

using the same directory as the php.ini error log.

Prolog will list and display that one too. It must be managed to prevent it from becoming too large and crashing the system with out-of-memory errors.

See PHP error log for more complete information on setting up error logs in different environments

More About Error Files and Log Dates

Archived error files and error items use the date set in the date.timezone directive in the php.ini file. If not set, GMT will be used.

On a live site with shared hosting, you may be able to set the timezone by creating a php.ini file in your document root and entering directives, for example:

date.timezone = America/Phoenix
error_log = /home/bisbeefa/mylogs/php_error.log

It may take 20-30 minutes or more for the changes to take effect on shared hosting, so be patient.

You may also be able to add the following to your site's main .htaccess file for both error_log and date.timezone:

<IfModule php7_module>
   php_value date.timezone "America/Phoenix"
   php_value error_log "/home/bisbeefa/mylogs/php_error.log"
</IfModule>

If you are still using PHP 5, change the first line above to reflect that.

My web host (Bluehost) also uses the following:

<IfModule lsapi_module>
   php_value date.timezone "America/Phoenix"
   php_value error_log "/home/bisbeefa/mylogs/php_error.log"
</IfModule>

lsapi is a drop-in module to speed up serving PHP pages.

TNG Version Compatibility

Prolog is compatible with TNG version 12.0 and up.

Mod Revision History

Version	Date	Updates
v15.0.0.22	8 Feb 2025	This is a rollback to fix an error which on some sites prevented logging.
v15.0.0.21	11 Jan 2025	Updates mod for TNGv15 Not compatible with previous versions of TNG. Removes double error reporting in logs. Updates the Prolog page.
v14.0.0.20	12 Mar 2024	Fixes clash between session filters in Mod Manager and Prolog.
v14.0.0.19	11 Mar 2024	User-selected log files and filters are now persistent during the same session. If you navigate away from the page and later return, the same log file and filter selections will apply. You must manually re-select another log file and clear the filter to change them.
v14.0.0.18	31 Jan 2023	Expands choices for error reporting level
v14.0.0.17	28 Jan 2023	Fixes warnings after log file is cleared
v14.0.0.16	1 Jan 2023	Fixes warnings Minor syntactic updates
v14.0.0.15	17 Dec 2022	Fixes filemtime problem in Windows
v14.0.0.14	14 Dec 2022	Not released
v14.0.0.13	10 Sep 2022	Updated to work with TNGv14 Inserts Prolog.conf.php into begin.php vice subroot.php to prevent conflict with the GEDCOM upload progress bar Checks for correct version of TNG before allowing installation Checks for uninstalled components of previous version of Prolog New mod editor option to set the timezone for the log entries Updated mod option to display errors to the screen: set to 0, only the public message displays; set to 1, only the raw PHP error is displayed (for developers) Moves prolog_conf.php file to the extensions directory
v13.0.0.9	21 Sep 2020	Updated to work with TNGv13 admin which no longer uses iframes. Removes external file version number Adds tooltip to Admin link showing version number
v12.0.0.9	21 Sep 2020	Removes external file version number Adds tooltip to Admin link showing version number
v12.0.0.8	10 Aug 2020	If no error log is defined in php.ini or elsewhere, Prolog creates a logs directory specified in the Prolog Edit Options.
v12.0.0.7a	13 Mar 2020	Fixed bug that prevented parameter updates
v12.0.0.7	12 Mar 2020	Now usese php.ini date.timezone vice GMT for timestamping Adds version number to copied files to avoid confusion when upgrading
v12.0.0.6	9 Mar 2020	More reliable trigger to archive PHP file to daily and start again Fixes bug that sends fatal error to yesterday's daily Fixes bug that kept out-of-date files from being deleted
v12.0.0.5	5 Mar 2020	Tested successfully with TNGv12.0 and up (version number adjustment.) Option to specify a log directory is removed. Works with error log defined in php.ini Both Prolog and PHP errors go to the php.ini error log At the end of each GMT day the PHP error log is sent to a dated backup log and the PHP error log is started anew. Keeps all of the day's errors in one place.
v12.2.0.4	3 Mar 2020	Fixes wrong support package bug Adds viewing and manipulation of all logs (PHP and system) in Prolog directory
v12.2.0.3	1 Mar 2020	Adds link to TNGWiki article Minor Update to language files
v12.2.0.2	24 Feb 2020	Initial release

Screen Shots

PC Based WAMPS Test Site

PHP Prolog link in the Admin page header menu. Note the daily log selected from the drop down list, and that the site's PHP version and current error reporting level are displayed in the prolog header bar. In the above example, All errors, notices, warnings and deprecations are being logged. A developer would want to show all errors and correct those thrown by their own mods or scripts, which can be isolated from any others by using the filter.

The filter searches each logged entry for a matching sub-string and displays the whole line if found. You could filter on a file name to display errors coming from just that script, or on 'Warning' to only see warnings, or 'Undefined: index' to only display those kinds of notices. After entering the filter string you can hit enter or click on the circular arrows to activate it.

Prolog Edit Options Screen

Installation

Prolog installs as a normal TNG mod. Download and unzip the contents -- one file and one folder. Place the prolog.cfg file and the support folder into your TNG site's mods directory. Do not remove folders and files from the support folder -- just leave them there. Navigate to your Mod Manager, find and open the mod listing and click on Install.

Upgrade

When installing an updated version of Prolog, it is important that you first use Mod Manager to completely remove any earlier version and preferably delete it.

Configuration

You must have a site-wide PHP error log set in your php.ini file, either by directly editing the file in a local WAMPS, or in shared hosting, indirectly by adding a php.ini (or user.ini) file to your TNG root directory with the error_log directive, for example:

error_log = /home/mysite/mylogs/php_error.log

The error log file should use the extensions .log.

Setting the Error Level for Logging

Error Level settings are designated by adding the index numbers for the items you want reported.

0 == ERRORS
1 == WARNINGS
2 == NOTICES
4 == DEPRECATED
9 == ALL

E_ERROR is always reported. Errors alone are index 0.

To specify E_ERROR and an additional type, enter the additional type index number into the parameter box. To specify a combination of error reporting, just add the index numbers and enter the total for the parameter.

A complete map:
0 == errors
1 == errors and warnings (1)
2 == errors and notices (2)
3 == errors and warnings and notices (1+2)
4 == errors and deprecated (4)
5 == errors and warnings and deprecated (1+4)
6 == errors and notices and deprecate (2+4)
7 == errors and warnings and notices and deprecated (1+2+4)
9 == E_ALL

• Error level 5 should be about right for a live site. It will log errors, warnings and PHP function deprecations. That latter means the scripts will stop working with new PHP upgrades, so we should know about them. Error level 1 would just be errors and warnings.

• Error level 9 logs everything -- errors, notices, warnings, deprecations and everything else. Because TNG emotes large numbers of notices right now, error level 3 should only be used while actually testing a script and reduced back to 1 or 5 when not testing. Even a daily log can get very large at error level 9.

Warning

If installed incorrectly this mod can cause the site to appear to crash. Don't panic. Edit subroot.php and remove the last line pertaining to Prolog. The site will come good again. Then go to mod manager and Clean up the partially installed Prolog mod. Prolog modifies subroot.php by including prolog_conf.php with parameters that are set in the mod's Edit Options. If the mod's Edit Options are incorrectly set or if the mod is partially installed for some reason, subroot.php may fail and so will all pages that include it.

Mod Manager Bug

There was a bug in Mod Manager up to TNGv12.3 beta which was corrected during testing. If a parameter expects a numeric value and you update it with and empty field, it renders a parameter variable such as $mycount

 $mycount = ;

That will cause a fatal error and the script containing the parameter will fail. After the fix to mod manager it will render it as

$mycound = 0;

.

Sites using this mod

If you download and install this mod, please add your TNG site to the table below:

URL	User	Note	Mod-Version	TNG-Version	User-language
A Bisbee Family History	Rick Bisbee	Mod Developer. A must-have for mod developers	12.0.0.7	12.1	EN
Our Roy and Boucher Family	Ken Roy	Using with Show PHP Error Log on test site	14.0.0.20 15.0.0.22	TNG 14.0.5 TNG 15.0	EN,FR
Roots & Relatives Remembered	Ron Krzmarzick	Public & Private	See here	See here	EN,DE,CS
Gilbert Family History	Warren Gilbert	Public	14.0.0.15	14.0	EN
Racines luxo-hennuyeres	Michel Kirsch	Registration	14.0.0.20	14.0.4	FR,EN,NL,DE,SP
Hooley Family Links	Rick Hooley	Public/Private, only used on test server	See Here	See Here	EN
R G Strong Family Genealogy	Russell Strong	Public/Private	14.0.0.18	14.0.4	EN,DE,FR,NL
Joseph Oran Holtz Genealogy Pages	Jim Holt	Private	See Here	See Here	EN
Pittsburgh O'Neils	Sean O'Neil			13.1.2	EN
Les Lapierre d'Amérique	Normand Lapierre	Public/Private site	14.0.0.16	14.0	FR,EN
The Severijns / Timmer Familytree	Rob Severijns	Public / Private	See here	See here	NL,EN
Zausmer Forest	Joyaa Antares	Private	14​.0​.0​.18	14.0.2	EN,FR
GénéaKat	Katryne	Public & private	14.0.0.18	14.0.4	FR,EN,SP
Stammbaum der Familie Datschetzky	Christian Datschetzky	Public	14.0.0.18	14.0.3	DE,EN
Development server	Brett	Local host	12.0.9, 15.0.0.2	12 - 15	EN
https://carverfamilytree.us	Bob Carver	Public/Private	14.0.0.20	TNG 14.0.4	EN