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Mod_Rewrite Basic Examples

mod_rewrite is very useful in many situations. Yet some behaviors were not so obvious when I started to mess with it. After many testings, I understand it much better, now. Having said that, I do not pretend to know it perfectly. I also make mistakes.

Htaccess

Preload flash .flv files into browser cache

How I was able to preload many flash flv and swf files on one of my clients sites that has a lot of online video and relatively small traffic. Their site visitors would usually watch 3-10 videos per visit and so to make the videos load almost instantly on every page I came up with a way to preload the top 10 .flv files and the swf flv player files as soon as the visitor successfully started watching the 1st video. Of course I also setup .htaccess caching on the server so that once they downloaded the files into their cache they would never request them from the server again. I was having fun with this so its pretty funky and uses some really cool combinations of javascript, swf preloader from xml, css classes to help automate it all..

Optimization

Mixed SSL Content Warning Secure Fixed

I used to run into the problem of having warning messages pop up when I accessed a page with secure and non-secure information and finally I found something that let me post non-ssl encrypted content on an ssl encrypted page and no warning messages will pop up!

Htaccess

PHP and AJAX shell console

Ever wanted to execute commands on your server through php? Now you can. I'm calling this file (see below) shell.php and it allows you to run commands on your web server with the same permissions that your php executable has.

Hacking

Creating an Offline Version of Page

I can do anythingSo, here's what I hacked together last night, that is being used today. It's essentially 2 files.

  1. A php file that scrapes uses curl to scrape all the urls for the page (favicon, css, images, pdfs, etc..)
  2. A simple bash shell script acting as a cgi that creates a zip file of all the urls, and a self-extracting exe file for those without a winzip tool

PHP

A better way to use PDF files online

.htaccess and php example serves .pdf files to give visitors the choice to open in an external program or save to disk without having to open it in the browser

PDF Before and after Fix - Firefox

PDF Output Broken FirefoxPDF Plugin Not Used Firefox

Htaccess

Redirect index.php to root

WordPress blogs show the same duplicate content for https://www.askapache.com/index.php and https://www.askapache.com/. If you've read about using a robots.txt file for WordPress SEO, than you already understand this setup results in Duplicate Content penalties being levied against your Blog and Web Site by Search Engines.

Htaccess

Caching Tutorial for Webmasters

If you examine the preferences dialog of any modern Web browser (like Internet Explorer, Safari or Mozilla), you'll probably notice a 'cache' setting. This lets you set aside a section of your computer's hard disk to store representations that you've seen, just for you. The browser cache works according to fairly simple rules. It will check to make sure that the representations are fresh, usually once a session (that is, the once in the current invocation of the browser).

Optimization

PHP to handle HTTP Status Codes for ErrorDocument

Fast, HTTP Protocol, protection. If you are reading this article, you already know enough about the benefits of making sure your site can handle HTTP Protocol Errors. This is a nice single php file with no dependencies or requirements, will work on anything. Optimized for minimizing bandwidth and resource-hogging connections from bots and spambots.

<?php
ob_start();
@set_time_limit(5);
@ini_set('memory_limit', '64M');
@ini_set('display_errors', 'Off');
error_reporting(0);

PHP

Rare XHTML elements use for SEO

Use these standards best-practices to achieve more powerful links in terms of SEO, EM, STRONG, DFN, CODE, SAMP, KBD, VAR, CITE, ABBR, and ACRONYM

SEO

Password Protection Plugin Status

Enumerating Permissions can be Annoying

Don’t ask me how because I won’t tell you, but on one of the hosts I was testing on that did not allow direct access I was able to get the Apache server running as dhapache to erroneously write a file into my users blog directory. This is a big security no-no and I now have my .htaccess file written into the blog directory where it should go, but instead of my php script’s user having write access to the file so I can modify it, its owned by dhapache! Because the file is owned by dhapache I shouldn’t even be allowed to know it exists, but there it is. So the next step was to try and take ownership of the .htaccess file so that I could modify it. I tried and tried but was unsuccessful, I couldn’t modify it so that was another dead end. Actually it took me awhile to figure out how to remove the file from my directory. Being that it was owned by dhapache I couldn’t delete or modify it using my php process or even through ftp/ssh! Sysadmins regularly run find commands that search the servers for any files owned by dhapache that should not be there as this is a big red flag that someone has found a way to manipulate dhapache which could potentially lead to modifying dhapache-owned server config files, which sometimes is all it takes to hack your website and server.. Luckily I was able to delete it by basically running the hack again to overwrite the file.

WordPress

Chmod, Umask, Stat, Fileperms, and File Permissions

Unix file permissions are one of the more difficult subjects to grasp.. Well, ok maybe "grasp" isn't the word.. Master is the right word.. Unix file permissions is a hard topic to fully master, mainly I think because there aren't many instances when a computer user encounters them seriously, and bitwise is oldschool. This contains a listing of all possible permission masks and bits from a linux, php, and web hosting view.... cuz you guys AskApache Regs Rock!

Security

Debug apache log files from php

Secure phpinfo.php with .htaccess, Now instead of getting a 404 error you will see debug information which will help you find out what the problem is.

PHP

Elite Log File Scrolling with Color Syntax

Scrolls the latest log entries for multiple log files to the current screen or to any other monitor or TTY in color using syntax highlighting, making debugging easier and saving a lot of time for multi-monitor workstations.

Linux

Serve Alternate Content based on Time

TIME_DAY Time RewriteCondTime-dependant rewriting uses mod_rewrite and apache server time variables to display different files depending on the time, while the URL stays the same. An often requested implementation of this is to display a different home page or image depending on if its morning, noon, or night.

Htaccess