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Awk Tutorial and Introduction

While researching a unix/linux tool awk I came upon one of the most thorough and helpful tutorials I've ever seen devoted to a particular topic. It's old-school just the way I like it. I contacted the author, Bruce Barnett because I just HAD to have this article for my readers, who are predominantly running solaris/unix/bsd/linux and he kindly gave permission.

Linux

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

Custom Boot Menu in Windows XP

Advanced XP Boot MenuOne of the first things that I do upon receiving a new Windows computer is immediately create a poweruser-style customized boot menu. Then every time I boot I can choose Safe Mode, Recovery Console, Debug, whatever I want! It's quick and easy to set-up and everyone should have one, soo sweet!

Windows

Notes from Apache HTTPD Source Code

thought I'd take a break from coding and post about how open-source is such a great tool for finding the best answers to the toughest questions,

/** is the status code informational */
#define ap_is_HTTP_INFO(x)         (((x) >= 100)&&((x) < 200))
/** is the status code OK ?*/

#define ap_is_HTTP_SUCCESS(x)      (((x) >= 200)&&((x) < 300))
/** is the status code a redirect */
#define ap_is_HTTP_REDIRECT(x)     (((x) >= 300)&&((x) < 400))

/** is the status code a error (client or server) */
#define ap_is_HTTP_ERROR(x)        (((x) >= 400)&&((x) < 600))
/** is the status code a client error  */

#define ap_is_HTTP_CLIENT_ERROR(x) (((x) >= 400)&&((x) < 500))
/** is the status code a server error  */
#define ap_is_HTTP_SERVER_ERROR(x) (((x) >= 500)&&((x) < 600))

/** is the status code a (potentially) valid response code?  */
#define ap_is_HTTP_VALID_RESPONSE(x) (((x) >= 100)&&((x) < 600))

Hacking

30x Faster Cache and Site Speed with TMPFS

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.

Optimization

DreamHost Server IP Address List

A list of all DreamHost Servers and corresponding IP address. The dreamhost.com DNS zone is currently having troubles, so most hostnames within this zone are not resolving.

Hosting

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.

Optimization

TMUX

penguin-tmuxarchlinux-on-macStop wasting your lives with Mac Terminals.. or Macs. Get a real machine and then get a real shell multiplexer! For many years we all loved GNU Screen, but tmux is by far a better option today. The only time I am in the shell and not using a multiplexer, is when I'm not on one of my machines. My Arch Linux machines all run URxvt and my .bash_profiles all start tmux automataically, whether in X or single-user mode, tmux is where it's at.

Hacking, Linux

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

Optimized Vimrc with 256 Colorscheme

askapachecode 256color colorscheme and vimrc screenshotThis is not your everyday vimrc. This is my personalized vimrc.. works especially great on remote servers, in tmux, screen, etc.

This doesn't require a git checkout, a vim update, a bash update, an OS update, a plugin. No. 1 vimrc, 1 colorscheme, just use curl to download and it's on. I use this on Arch Linux, NetBSD, FreeBSD, OpenBSD, Debian, Ubuntu, Cent OS, Red Hat, and that's mostly it so far.
If you aren't already using vim as your primary editor in a powerful way, you are gonna owe me for this.

Linux

ASCII Chart

Wanted to stick this here for a reference, mostly for me. I use ASCII alot in bash, preg_matches, preg_replace, etc..

Linux

Crazy POWERFUL Bash Prompt

bash power prompt PS1This 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

Linux

DNS Round Robin Configuration using Rsync over SSH

The goal is to add the HostGator server to be an exact mirror of the s.askapache.net domain, then to add that server as a 2nd A record to my DNS zone. That way half the visitors to the size will be taking up resources and bandwidth on the HostGator server instead of mine.

Round Robin A records in DNS are intended to evenly distribute queries between each host of the same name. Using some tricks straight out of a hackers toolbox we can verify if the distribution is taking place. (It is.)

Optimization

Hacking VLAN switched networks

Bypassing VLAN security on networked switchesThere isn't much vlan info on the net in terms of specifics and I had to learn all about it because I needed to log in to a switch that was on a different vlan. With the help of the Ettercap developers NaGA and ALoR I figured it out.

Originally Posted: 3/30/2004

Hacking

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);

PHP

Optimize a Website for Speed, Security, and Easy Management

Learn how to setup, configure, secure, optimize, and create a low-maintenance website the AskApache way. I'm piecing together all the hacks, tricks, methods, and ideas discussed throughout this blog and all across Netdom and glueing them all together to show you how to have the most optimized, crazy fastest, and best website setup I can think of.

Hosting

View all MySQL Variables for Pasting into my.cnf

mysql-variables-my-cnf-fileThis is really useful for me because I work with dozens of different database servers. The first thing I do is run this command and paste it into the servers /etc/my.cnf file. That way I will always know the original value and it just makes life much easier.

$ mysql -NBe 'SHOW VARIABLES' |sed 's,\t,^=,'|column -ts^|tr "\n" '@'|eval $(echo "sed '" "s,@\("{a..z}"\),\n\n\1,;" "'")|tr '@' "\n"|sed 's,^,# ,g'

MySQL

Debugging Tools for Windows

I am almost ready to publish the final tutorial on using ssh tunnels from a truecrypt partition on a Windows machine. Of course I choose to go way overboard in my research and the tutorial is full of some pretty awesome windows tricks.. I will come back to this post soon and post all the other advanced tools I use for debugging windows, for now though you MUST know how to debug the kernel and use these basic debugging tools.

Windows

Mod_Security .htaccess tricks

Mod_Security rivals Mod_Rewrite in the amount of features it provides. I decided to go ahead and post what I learned about it today, even though its tough to give away such awesome htaccess and apache tricks.. Learn how to control spam once and for all, conditionally log/deny/allow/redirect requests based on IP, username, etc.. Mod_Security is so fine!

Htaccess

.htaccess Plugin Blocks Spam, Hackers, and Password Protects Blog

.htaccess security plugin 2

Well what can I say, other than this is sooo DOPE! Here is a list of the modules this plugin (version 4.7 unreleased) will automatically detect. I compiled the list myself using every module included with any default Apache installation for ALL the versions listed below, 1.3 to 2.2+

Want to know something else I'm including in this plugin? For each and every module that is detected, this plugin can then detect ALL of the modules .htaccess Directives! For instance, RewriteRule, AccessFileName, AddHandler, etc.. are each a directive belonging to a module that is allowed to be used from within .htaccess files.

Talk about sick.. these tricks have the diamond disease!

WordPress