strace+ is an improved version of strace that collects stack traces associated with each system call. Since system calls require an expensive user-kernel context switch, they are often sources of performance bottlenecks. strace+ allows programmers to do more detailed system call profiling and determine, say, which call sites led to costly syscalls and thus have potential for optimization.
Linux gcc linux strace
There 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 Hacking security
Hosting
CSS is one of the most useful tools I have in my toolbox as a Web Developer. Having a CSS Toolbox containing good CSS Classes that you repeatedly use is quite helpful for us XHTML / web-standards / best-practices developers. Check out 10 of my favorite CSS classes.
CSS
Ok, so on a site like this one, there is a tremendous amount of 'code' styled with CSS fonts in a pre, code, var, tt, samp, or kbd html tag. When using an programming tool like VIM to write code it is shown beautifully using your OS fonts. So then, how can we get that same font beauty to be there on the web? And, of course the solution must use best-practices (and preferably only use CSS and (X)HTML).
Also, text effects! --> View Solution
CSS font Google
As an example, here is the boot line that I am using at the moment on an older Dell Desktop, just to illustrate module parameters and environment vars.
title Arch Linux X-256
linux /vmlinuz-linux root=UUID rw rootfstype=ext4 elevator=noop selinux=0 plymouth.enable=0 raid=noautodetect ipv6.disable=1 video=DP1:d rcutree.rcu_idle_gp_delay=1 i915.panel_ignore_lid=-1 i915.modeset=1 TERM=rxvt-256color
Linux Arch Linux Boot GRUB Kernel
A lot of the past and upcoming articles on AskApache are focused on speeding up a server or website, or just making things more efficient. I'm starting several speed tip articles that require the following 3 programs if you want to follow along, that is... if you can keep up! ;)
Software
Before
After trick
I am often logged in to my servers via SSH, and I need to download a file like a WordPress plugin. I've noticed many sites now employ a means of blocking robots like wget from accessing their files. Most of the time they use .htaccess to do this. So a permanent workaround has wget mimick a normal browser.
Linux bash wget
How to password-protect, Allow or Deny a visitor based on a condition. If you are having trouble getting htaccess-based password protection to work see: Troubleshooting htaccess Authentication: Getting it to work
Htaccess AuthName AuthType FilesMatch Htaccess Password Password Protection Require
Htaccess php tips and tricks for the Apache HTTPD Web Server, mostly these tips show you how to run customized versions with customized php.ini files, I require custom php.ini files because they are so useful!
PHP
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 Assemblers basic debugging tools Debug Debuggers Debugging Kernel
Use php.ini to add HTTP Headers to output PHP
If you remove the Last-Modified and ETag header, you will totally eliminate If-Modified-Since and If-None-Match requests and their 304 Not Modified Responses.
Htaccess Cache Caching ETag Htaccess Last-Modified
A first-time visitor to your page will make several HTTP requests to download all your sites files, but using the Expires header you make those files cacheable. This avoids unnecessary HTTP requests on subsequent page views.
Htaccess Expires FilesMatch Header Htaccess
Hacking
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
The idea is to use CSS to have the browser display programming and code similar to the high-quality look of a developers machine, like this older screenshot of my VIM.
CSS Digital typography Typeface Typesetting Typography
Nifty SEO tip to get Search Engine Bots to check your site every hour until you finish working on it and tell them you are finished.
SEO
Thought I'd give you all the tips and tricks that I've learned and use when developing WordPress plugins.. which can be quite fun!
WordPress
Htaccess 301 Redirects Htaccess
Get your real server info
Htaccess
List of the directives available to Powweb users for use in htaccess files Htaccess
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
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 DNS HostGator Rackspace Round-Robin WiredTree
If you want to redirect to a different version of a file based on the time, this code is for you! Please read: Serve Alternate Content based on Time
Htaccess
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
One 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
Google AdSense calles their AdSense Ads, "Sponsored Links", while Text-Link-Ads.com recommends "Sponsored By". Of course it is against the Google Adsense TOS to rename your ads, but in general, for non-adsense, what do you like to call your sponsored links?
SEO
Grab the latest php.ini developmental version and discover new or previously hidden php runtime configuration settings... ahead of everyone else!
PHP
WordPress uses a file named .htaccess to rewrite all requests to the main index.php file. This article explains what the htaccess file rules look like and what they actually do.
Htaccess Htaccess wordpress
Want to block a bad robot or web scraper using .htaccess files? Here are 2 methods that illustrate blocking 436 various user-agents.
Htaccess