Server Administration

Server Administration

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PHP Session File Hacks

What they say about kung-fu is true..

It can be attained by anyone through hard work over time. You can become as good as the amount of work you put in. Here’s a short look at a basic technique that I use. Simply reverse engineering the source code and taking notes along the way…

static void php_session_send_cookie(TSRMLS_D)
  if (SG(headers_sent)) {
          if (output_start_filename) {
                  php_error_docref(NULL TSRMLS_CC, E_WARNING, "Cannot send session cookie - headers already sent by (output started at %s:%d)",
                          output_start_filename, output_start_lineno);
          } else {
                  php_error_docref(NULL TSRMLS_CC, E_WARNING, "Cannot send session cookie - headers already sent");
          }
          return;
  }
 
  /* URL encode session_name and id because they might be user supplied */
  e_session_name = php_url_encode(PS(session_name), strlen(PS(session_name)), NULL);

· session  ·  RSS | 8:00 PM

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Crazy POWERFUL Bash Prompt

This amazing bash linux prompt does more than meets the eye. If you want to know how to become really good with technology, linux is the secret sauce behind the AskApache articles. Open Source is elixir of the web. Thanks to everyone who helped me for the past 20 years. I use linux/bsd because homey don’t play, so this is geared to be as productive a prompt as I can make it.

Don’t have much time.. or just don’t care? Not a problem, here are the 3 lines to copy and paste – you can just paste them right in your shell to test it, or add to a startup script.

export AA_P="export PVE=\"\\033[m\\033[38;5;2m\"\$(( \`sed -n \"s/MemFree:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\` / 1024 ))\"\\033[38;5;22m/\"\$((\`sed -n \"s/MemTotal:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\`/ 1024 ))MB\"\\t\\033[m\\033[38;5;55m\$(< /proc/loadavg)\\033[m\";echo -en \"\""
export PROMPT_COMMAND="history -a;((\$SECONDS % 10==0 ))&&eval \"\$AA_P\";echo -en \"\$PVE\";"
export PS1="\\[\\e[m\\n\\e[1;30m\\][\$\$:\$PPID \\j:\\!\\[\\e[1;30m\\]]\\[\\e[0;36m\\] \\T \\d \\[\\e[1;30m\\][\\[\\e[1;34m\\]\\u@\\H\\[\\e[1;30m\\]:\\[\\e[0;37m\\]\${SSH_TTY} \\[\\e[0;32m\\]+\${SHLVL}\\[\\e[1;30m\\]] \\[\\e[1;37m\\]\\w\\[\\e[0;37m\\] \\n(\$SHLVL:\\!)\\\$ " && eval $AA_P

· Tricks  ·  RSS | 3:02 PM

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Questions I Ask Web Hosting Companies, Before Buying

The following is a transcript of a chat I had with a company called tektonic, and at that time I was looking for a cheap linux host to use for some redundancy/failover operations. I generally contact a new hosting company like this every few months.. I like to have options available in case of some kind of failure or network attack, so it’s always a good idea to have a few ace linux servers in your back pocket.

If you’ve read any other articles on AskApache, you can see a certain obsession towards optimization, speed, and security — so that is the purpose of the following questions.

· buying  ·  RSS | 6:15 AM

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HOWTO: Uninstall CPANEL over SSH

The following is just a quick reference of some of the commands I used to uninstall cpanel. This is for advanced users of the shell. If you aren’t that advanced and you run a single one of these commands without fully understanding it, you will probably kill your server, probably lose everything on it permanently, probably not have a website or email for weeks.. So backup all your data FIRST. Also, if you aren’t 100% sure you won’t run into problems, you should contact your hosts technical support – but be prepared for some MAJOR negativity.. cpanel makes things very easy for hosts, and the last thing tech support wants is to fix a server broken by someone who doesn’t know what they are doing.

· administration  ·  RSS | 2:55 PM

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Real-Life Htaccess Files from My Server

#### No https except to wp-admin -
# If the request is empty ( implies fopen or normal file access by a php script )
RewriteCond %{THE_REQUEST} ^$ [OR]
 
# OR if the request if for wp-admin or wp-login.php
RewriteCond %{REQUEST_URI} ^/(wp-admin|wp-login\.php).*$ [NC,OR]
 
# OR if the Referer is https
RewriteCond %{HTTP_REFERER} ^https://www.askapache.com/.*$ [NC]
 
# THEN skip the following rule, basically all this does is force https or badhost to be redirected
# BUT because of the above 3 rewritecond's, this won't break poorly written admin scripts
RewriteRule .* - [S=1]
 
RewriteCond %{HTTPS} =on [OR]
RewriteCond %{HTTP_HOST} !^www\.askapache\.com$ [NC]
RewriteRule .* http://www.askapache.com%{REQUEST_URI} [R=301,L]
 
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /(wp-admin/.*|wp-login\.php.*)\ HTTP/ [NC]
RewriteCond %{HTTPS} !=on
RewriteRule .* https://%{SERVER_NAME}%{REQUEST_URI} [R=301,L]

· .htaccess file  ·  RSS | 11:06 AM

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30x Faster WP-Super Cache Site Speed

NOT a typo.. 30x is measurable, well-documented, and easily tested. This is what open-source is about. I haven’t had time to post much the past year, I’m always working! So I wanted to make up for that by publishing an article on a topic that would blow your mind and be something that you could actually start using and really get some benefit out of it. This is one of those articles that the majority of web hosting companies would love to see in paperback, so they could burn it.

· Super  ·  RSS | 11:43 AM

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Advanced WordPress wp-config.php Tweaks

The bottom line for this article is that I want to make WordPress as fast, secure, and easy to install, run, and manage because I am using it more and more for client production sites, I will work for days in order to solve an issue so that I never have to spend time on that issue again. Time is money in this industry and that is ultimately (time) what there is to gain by tweaking WordPress.

Note: I spent no time on readability, this is primarily a read the code and figure it out article.. This is for advanced users looking for a reference or discussion and for those of you looking to advance. Feedback would be great if you make it that far..

· WordPress  ·  RSS | 3:23 AM

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HTTP Status Codes and .htaccess ErrorDocuments

There are a total of 57 HTTP Status Codes recognized by the Apache Web Server. Wouldn’t you like to see what all those headers and their output, ErrorDocuments look like?

· status  ·  RSS | 3:56 PM

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Vetted – Top 3 WordPress Speed Plugins

There are so many WordPress plugins out there now that I wanted to post my favorite 3 plugins for speeding up a WP-Powered blog. These are the 3 plugins that I install for pretty much all of my WP-Powered sites, which I run about 300 now. They work together to provide a very optimized blog for speed.

DB-Cache Reloaded does something entirely different, it saves the mysql queries that are made to the WP-database, as well as the mysql results to static files, and then through php serves those cached-files instead of re-querying the mysql database. Most mysql databases are stored on separate servers, and although many are on the same local network there is a limit to how many queries, and how many connections can take place.

So DB-Cache Reloaded basically makes WP-Super Cache work alot faster when generating the cache files, and DB-Cache Reloaded helps in a number of areas un-related to WP-Super Cache, like in the admin panel. And DB-Cache without WP-Super-Cache is a joke because it still uses the application-level and php for everything. Gotta use both (or just WPSC).

· caching  ·  RSS | 2:14 PM

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Optimizing Servers and Processes for Speed with ionice, nice, ulimit

To prepare for several upcoming articles on AskApache that are focused on optimizing Servers and Sites from a server admin level, here is an article to introduce the main tools that we will be using. These tools are used to optimize CPU time for each process using nice and renice, and other tools like ionice are used to optimize the Disk IO, or Disk speed / Disk traffic for each process. Then you can make sure your mysqld and httpd processes are always fast and prioritized.

· renice  ·  RSS | 1:41 AM

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mod_rewrite Fix for Caching Updated Files

Web Developers sometimes use file.ext?v=004 as a version control system to force visitors to use updated files. This is terrible. Instead link to apache-003.css and set it to be cached forever. When you change the file you just change the links to apache-004.css. That eliminates millions of bandwidth and resource robbing If-Modified-Since requests. You only need Apache with mod_rewrite, and 1-10 minutes!

· version  ·  RSS | 9:20 AM

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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.

· ajax  ·  RSS | 9:01 PM

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Htaccess SetEnvIf and SetEnvIfNoCase Examples

SetEnv, SetEnvIf, and SetEnvIfNoCase directives conditionally set environment variables accessible by scripts and apache based on HTTP Headers, Variables, and Request information.

• Unique mod_setenvif Variables
• Populates HTTP_MY_ Variables with mod_setenvif variable values
• Set REMOTE_HOST to HTTP_HOST
• Allows only if HOST Header is present in request
• Add values from HTTP Headers
• Set the REDIRECT_STATUS for Interpreter Security

· Examples  ·  RSS | 1:36 PM

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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. I’ve done a lot of research on it the past couple weeks… and now here’s everything I’ve learned so far.. cuz you guys AskApache Regs Rock!

· Stat  ·  RSS | 6:16 AM

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SEO Secrets of AskApache Part 2

This is part II of the Advanced SEO used on AskApache.com Series and describes how to control which urls are indexed by Search Engines and how to move them higher up in Search Results.

· advanced  ·  RSS | 5:44 PM

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Mod_Rewrite Variables Cheatsheet

We’ve figured out what mod_rewrite variables look like, a cheatsheet of the actual value.

· Rewrite  ·  RSS | 1:05 AM

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Pimp out your FeedBurner Count

I’ve had a lot of people ask about the FeedBurner FeedCount image on AskApache. Specifically how to set it up with custom messages and different colors each page view… It is pretty sweet..

· Count  ·  RSS | 4:50 AM

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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.

· logs  ·  RSS | 12:56 AM

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Encrypted WordPress / phpBB Backups

Enter your DOMAIN_ROOT and the location of your wp-config.php or config.php, and this script finds all the mysql settings by parsing the phpbb or wordpress config file, then creates GPG encrypted backups, and saves your settings for future automation.

· Encrypted  ·  RSS | 12:28 PM

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Blocking Bad Bots and Scrapers with .htaccess

Want to block a bad robot or web scraper using .htaccess files? Here are 2 methods that illustrate blocking 436 various user-agents.

· Bots  ·  RSS | 11:04 AM

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