linux
Linux
Linux scheduler
GNU / Linux
GNU/Linux
linux.bash
Arch Linux
King Penguin Linux Notebook
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
Linux Debugging using a Bootloader with Kernel Parameters
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
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.
Share a Mouse and Keyboard between Windows and Linux
Install multiple OS Without Cds
Orig published 2006. I had a CD-RW drive but being a computer security researcher I had no money for blank cd-recordables. What follows is how I managed to install various operating systems on my computer (1 hard drive) without having to burn to a CD the ISO and then boot from that.
And also:
==Phrack Inc.==
Volume 0x0b, Issue 0x3f, Phile #0x0a of 0x14
|=-----------------=[ Hacking Grub for fun and profit ]=-----------------=|
Fix Linux Users Home Permissions with a Cron Job
As a security nut myself, and also a Linux admin, one of my biggest pet peeves is when I've taken the time and care to segment all the users on a server into separate home directories, and then some developer comes along, logs in as root, and changes the ownership of files. Other things can cause this, like Apache, PHP, Mutt, etc.. So I've always used a cron job that executes daily (and on demand) which automatically fixes all the permissions back to what they should be.
Custom bash_profile for Advanced Shell Users
Looking for some advanced uses for the shell? Here is some of my best. The shell is where 70% of my work takes place, and I have at least one terminal open almost 100% of the time, for viewing tailing color-coded logs, and of course for the SSH Tunnels that I use to route various networking through, like my email. So I decided that to standardize and create a bash_profile containing the most time-saving and helpful functions that I could use on all the various hosting environments would really be some sweet sugar, so here is my constant Work-in-progress.
It works for all shells I encounter, including BackTrack, Debian, Knoppix, Arch Linux, etc. Also works for many hosting environments I use including DreamHost, HostGator, WiredTree, and pretty much any linux VPS.
I also rely on this heavily from within shell scripts I write to access all the functions and stuff in this .bash_profile, and to do that I just do like:
#!/bin/bash source ~/.bash_profile &>/dev/nulll pm "PM is a function to output nice messages with color" yn "Are you enjoying the shell" && pm "Thats great!" || pm "Perhaps you're better suited for DOS" yn "Show Calendar" && aa_calendar yn "Show Fortune" && aa_fortune
Failover SSH for Linux Web Hostmasters
COMPUTER SECURITY TOOLBOX
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.TMUX
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.
Building strace-plus
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.
Bash alternative to Reflector for Ranking Mirrors
A pure bash alternative to the python reflector, using curl, xargs, and sort for ranking Arch Linux mirrors.
Nice and simple. Short and sweet.
MySQL Performance Tuning Scripts and Know-How
Unless you are a total linux-freak-guru like myself, and even if you are, it can be enormously challenging and somewhat overwhelming to locate and eliminate MySQL bottlenecks. While many DBAs focus on improving the performance of the queries themselves, this post will focus on the highest-impact items: MySQL Server Performance and OS Performance for MySQL. Specifically showing 4 awesome tools to auto-tune your MySQL and a few more tools just for monitoring!
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.
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Hacking VLAN switched networks
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
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.
SUDO – sudoers Config File
HOWTO: Uninstall CPANEL over SSH
The following is just a quick but detailed reference of some of the commands I used to successfully uninstall cpanel permanently. This is for advanced users of the shell. If you run a single one of these commands without fully understanding it, you will probably kill your server, lose everything on it permanently, not have a website or email for weeks.. So backup everything. FIRST. You should also contact your hosting provider support - but be prepared for some MAJOR negativity.. cpanel makes things very easy for web-hosting companies, and you are less than a drop in their bucket.
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.
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!
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.
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
Upgrading to DreamHost Private Servers
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.
Optimized Vimrc with 256 Colorscheme
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.
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.
Undetectable Sniffing On Ethernet
I have been in some tight spots where I had to sniff a password or two off the wire, or sniff some packets off the wire and based on the packets content perform some action... Accidentally, I stumbled on a method to sniff data while remaining undetected and invisible.
Originally Posted: 2003/04/15
Internet Census 2012 – Port scanning using insecure embedded devices – Carna Botnet
While playing around with the Nmap Scripting Engine (NSE) we discovered an amazing number of open embedded devices on the Internet. Many of them are based on Linux and allow login to standard BusyBox with empty or default credentials. We used these devices to build a distributed port scanner to scan all IPv4 addresses. These scans include service probes for the most common ports, ICMP ping, reverse DNS and SYN scans. We analyzed some of the data to get an estimation of the IP address usage.
Apache Web Server Speed Configuration Hacks
Apache server performance can be improved by adding additional hardware resources such as RAM, faster CPU, etc.Advanced Windows Batch File Scripting
If for some reason you need to use windows .bat batch file scripting to do some task, or you just want to learn the most universal batch programming language on Windows machines, you lucked out and found the AskApache example. My expertise is the shell, in this article the shell is Windows cmd.exe. It has some pretty advanced windows shell usage, including pipes and redirection, but it's the modular linux-like coding approach that earns this script it's "advanced" title.
:SETPROMPT set PROMPT=$_[%USERNAME%@%USERDOMAIN%]$S[$P]$_$M$G && EXIT /B
My favorite tool (and I've tried sooo many) for editing most Windows files and especially .bat files is the free and open-source Notepad++. Set that up and you will have a color-syntax-highlighted editor for Batch Scripting that works very very well.
ASCII Chart
Wanted to stick this here for a reference, mostly for me. I use ASCII alot in bash, preg_matches, preg_replace, etc..