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 chmod File Permissions umask
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?
Htaccess 403 404 500 503 Htaccess mod_rewrite PHP RewriteCond RewriteRule
This is a big update from the last time I looked into this, when I enumerated 57 Status Codes that Apache 2.x was capable of handling. This list contains 83 Status Codes recognized by Apache. I compiled the latest 2.4.4 Apache in order to view the actual codes sent by a live server.. very cool. You can read about the newest HTTP Status Codes in RFC 6585.
Net Apache cURL ErrorDocument Htaccess HTTP HTTP Headers Redirect Status Code
2 awesome ways to implement caching on your website using Apache .htaccess or httpd.conf. Both methods are extremely simple to set up and will dramatically speed up your site! Htaccess Cache Cache-Control ETag Expires Header Headers Htaccess mod_expires mod_headers
Quick and easy method to get a list of all Apache Modules currently loaded, a list of all the directives each module provides, a list of currently used directives, etc... These directives can be used in httpd.conf and/or .htaccess files so it is definately useful to know which ones are available and which ones are currently being used.
Htaccess Apache bash lynx mod_rewrite mod_status server-info server-status
Using FastCGI on DreamHost and .htaccess
Shell Scripting
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
Apache, Hosting 2.4 Apache Error
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 Apache HTTP Server Caching Htaccess HTTP linux operating systems round-robin DNS technology Web Developer Web server
An image and technicacl achievement so profound, it will touch yoour heart.. So 3D... it'll hurt you eyes! LOL.. lol.. Man I am cracking up here. haha Ha definately the best intro ever, those really do look 3D for terminal though huh.. Sweet. Here is the little function I wrote to output that grey marble.
Linux ANSI escape code ANSI.SYS Control characters Escape sequence Stty Termcap Terminfo Tput
If you have a php.cgi or php.ini file in your /cgi-bin/ directory or other pub directory, try requesting them from your web browser. If your php.ini shows up or worse you are able to execute your php cgi, you'll need to secure it ASAP. This shows several ways to secure these files, and other interpreters like perl, fastCGI, bash, csh, etc.
Htaccess Apache HTTP Server CGI Common Gateway Interface Htaccess HTTP 403 interpreter PHP php interpreter php.ini security SuEXEC
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
Recently I had to setup a script to curl 10k urls, but it could only do 500 requests at any one time. In order to work under that limit, I created a function that returns the number of currently running processes on the machine in an extremely fast and efficient way, thus allowing the curl_multi requests to queu themselves such as GNU xargs.
PHP /proc clearstatcache Hard link PHP Process stat version_compare
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 CFQ Idle linux Linux scheduler Load Nice RAM Scheduling algorithms
Linux firewall nmap
#### 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 .* https://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 RewriteCond RewriteEngine RewriteRule
Say you want to deny access to your entire site except when you access it. The following htaccess code does just that.
Instead of a Static IP you could also use a hostname, or part of a hostname..
Htaccess
.htaccess is a very ancient configuration file for web servers, and is one of the most powerful configuration files most webmasters will ever come across. This htaccess guide shows off the very best of the best htaccess tricks and code snippets from hackers and server administrators.
You've come to the right place if you are looking to acquire mad skills for using .htaccess files!
Apache, Hosting, Htaccess, Optimization, Security, SEO, Web Development, WordPress .htpasswd 301 Redirect Apache Apache HTTP Server Cache Hosting Htaccess Htaccess Software HTTP Headers httpd.conf HyperText Transfer Protocol mod_rewrite Redirect RewriteCond RewriteRule SSL
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
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 ErrorDocument HTTP PHP
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).
WordPress Cache Web server wordpress
Hosting, Htaccess, Linux, PHP Htaccess php-fpm
List of mainly obscure security software geared more for the master pentester. These are mostly for unix, bsd, and mac and many are difficult to install and setup (require custom servers, inside access points, obscure libraries). Only programs that output data are included, so no actual exploits or anything. Most of these output extremely useful albeit extremely technical information. Security
Apache server performance can be improved by adding additional hardware resources such as RAM, faster CPU, etc. Optimization
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 mod_security security
Learn about the 7 different HTTP response codes specifically reserved for redirection. 301, 302, 303, 304, 305, and 307.
SEO
DreamHost PS gives you your own "virtual machine", protecting your CPU and RAM on your physical machine for faster websites. Here's what I like and dislike about DreamHostPS, and some of the issues and solutions for migrating.
Hosting DreamHost
Advanced Web Development by AskApache is a Firefox Collection I created since I'm always trying new Addons out and using multiple computers and I wanted a quick and easy way to install my favorite's and keep a running list. Firebug, YSlow, LastPass, and Web Developer are the only ones I always use regularly.
I like the idea of the last.fm but it's not as powerful as the site, which is awesome. Lately listening to Kings of Leon Radio...
Software Addons Firefox Mozilla
This 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 .vimrc 256 Color Vim
FallBackResource is a great alternative to using mod_rewrite to direct Apache to send all requests for non-existing files/directories to a script in WordPress. Htaccess and Server Config enabled.
Apache, httpd 2.4 FallbackResource Htaccess mod_dir mod_rewrite RewriteBase RewriteRule wordpress
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 tmpfs
I really really wanted to run the latest MariaDB with LZ4 Page Compression.. it is a game changer for many types of large databases I deal with. So I compiled it manually in a way that is repeatable and follows best-practices and it's now powering this site. Now I can use InnoDB Page Compression with lzo, lzma, bzip2, snappy, or my favorite algorithm: LZ4.
Thought this would be a good chance to post a howto, and show that there is a lot you can do by compiling software yourself and breaking the package management one-click install shackles.
Linux, MySQL centos compression InnoDB lz4 MariaDB MySQL
Stop 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 linux.bash Screen shell tmux
The machine itself is super super ultra-thin, wafer thin, very cool looking. It's crazy light, I was amazed how slick it looked when it arrived.
Huge amount of open-source hardware/chipsets/etc.. The first time I went through the dmesg I was smiling. 2 USB 3.0 ports, and they actually work as promised, very very fast transfer speeds to my USB 3.0 external SSD. Incredible speed, boot time is the fastest I've ever seen. Starts at $720, mine was $1,800
Products Arch Linux firmware/software GNU GNU / Linux Laptop linux Notebook Solid-state drive thinkpenguin USB 3.0 usb wireless-n adapter
