background preloader

HowtoForge - Linux Howtos and Tutorials

Related:  Linux

Beginner's Guide to Nmap Ever wondered how attackers know what ports are open on a system? Or how to find out what services a computer is running without just asking the site admin? You can do all this and more with a handy little tool called Nmap. What is Nmap? Short for "network mapper," nmap is a veritable toolshed of functionality to perform network scans. It can be used for security scans, simply to identify what services a host is running, to "fingerprint" the operating system and applications on a host, the type of firewall a host is using, or to do a quick inventory of a local network. It's famous, too. In this tutorial, I'll cover some of the basics of using Nmap and provide some examples you can use quickly. Getting Nmap and Basic Use You'll find Nmap packaged for most major Linux distros. The basic syntax for Nmap is Nmap Scan Type Options target. nmap -O Note that Nmap requires root privileges to run this type of scan. As you can see, Nmap provides a lot of data. Practice Hosts Zenmap

XenoCafe - Learn Linux the easy way with our free comprehensive tutorials for beginners Uninstall Survey Recently I was developing at home, where I do not have Visual Assist; it was so much slower. It was like programming with stone knives and bearskins. Visual Assist has been so good I don't notice it anymore – until I use an IDE without it. Then, I wonder what's wrong with the IDE. David Smith Tyco Electronics We rely heavily on Visual Assist in my office. Rasmus Anthin Surgical Science Inc Visual Assist has proven to always increase productivity. Kristoffer Danielsson Kaysoft Been using Visual Assist for quite a few years now and it's just gotten better and still better! John West Microsoft, PTLS Test Tech. I've become addicted to Visual Assist at work. Your product and support are top of the line. Kristen Overmyer Halifax Biomedical Inc. Just really, really thank you. Adrian Edmonds CMosaix Ltd. Every time I hear a developer complain about C++ support in VS, I point them to you guys. Chris Tartamella Bentley Systems, Inc. Your product is just awesome and I can't code without it.

Useful Unix commands for data science | Greg Reda Imagine you have a 4.2GB CSV file. It has over 12 million records and 50 columns. All you need from this file is the sum of all values in one particular column. How would you do it? Writing a script in python/ruby/perl/whatever would probably take a few minutes and then even more time for the script to actually complete. Thankfully, the Unix utilities exist and they're awesome. Let's assume our data, which we'll call data.csv, is pipe-delimited ( | ), and we want to sum the fourth column of the file. cat data.csv | awk -F "|" '{ sum += $4 } END { printf "%.2f\n", sum }' The above line says: It took less than two minutes to run on the entire file - much faster than other options and written in a lot fewer characters. Hilary Mason and Chris Wiggins wrote over at the dataists blog about the importance of any data scientist being familiar with the command line, and I couldn't agree with them more. Other commands wc data.csv# 377 1697 17129 data.csvwc -l data.csv# 377 data.csv grep sed

Bash String Manipulation Examples – Length, Substring, Find and Replace In bash shell, when you use a dollar sign followed by a variable name, shell expands the variable with its value. This feature of shell is called parameter expansion. But parameter expansion has numerous other forms which allow you to expand a parameter and modify the value or substitute other values in the expansion process. In this article, let us review how to use the parameter expansion concept for string manipulation operations. This article is part of the on-going bash tutorial series. Refer to our earlier article on bash { } expansion. 1. ${#string} The above format is used to get the length of the given bash variable. $ cat #! To understand more about bash variables, read 6 Practical Bash Global and Local Variable Examples. 2. Bash provides a way to extract a substring from a string. Extract substring from $string at $position Extract $length of characters substring from $string starting from $position. 3. ${string#substring} ${string%substring} $ cat #! 4. 5.

How to Learn bash shell and scripting – The best tutorials for bash beginners Bash (Bourne-Again SHell) is a Linux and Unix-like system shell or command language interpreter. It is a default shell on many operating systems including Linux and Apple OS X. If you have always used a graphic user interface like KDE or Gnome or MS-Windows or Apple OS X, you are likely to find bash shell confusing. If you spend some time with the bash shell prompt and it will be difficult for you to go back. Here are a list of tutorials and helpful resources to help you learn bash scripting and bash shell itself. 1. BASH Programming - Introduction HOW-TO : This tutorials intends to help you to start programming basic-intermediate shell scripts. 2. 3. 4. 5. 6. 7. 8. bash -- Standard Shell : A thorough understanding of bash programming for Gentoo developers by Gentoo project. 10. 11. 12. 13. 14. 15. Have a favorite online bash tutorial or new books?

Cheat Sheet: Crontab by Example Today's article may be pretty basic for regular readers but hopefully some may find it useful. This article will cover creating a crontab entry and show some examples of common crontabs. The Cron daemon is a service that runs on all main distributions of Unix and Linux and specifically designed to execute commands at a given time. Creating crontabs is something every level of Unix/Linux Sysadmin should know like the back of their hand. Creating a New Crontab Before I start showing examples of crontabs I want to cover how to create a crontab from scratch. A crontab file is essentially a regular file located within /var/spool/cron/crontabs/. # ls -la /var/spool/cron/crontabs/ total 12 drwx-wx--T 2 root crontab 4096 Aug 12 15:30 . drwxr-xr-x 5 root root 4096 Jul 15 19:30 .. Before we put any data in them crontab files are nothing special, simply an empty file with a certain set of permissions. Example (As the user): username@workstation:~$ crontab -e Example (As root user): Crontab Syntax Comma or

Bash Hackers Wiki Front page [Bash Hackers Wiki] Getting Started with Weave and Docker on Ubuntu • Weave - All you need to connect, observe and control your containers What You Will Build Weave provides a software network optimized for visualizing and communicating with applications distributed within Docker containers. Using tools and protocols that are familiar to you, Weave’s network topology lets you to communicate between containerized apps distributed across multiple networks or hosts more quickly and efficiently. With Weave you focus on developing your application, rather than your infrastructure. Specifically, in this example: You will create a simple application running in two containers on separate hosts. This tutorial uses simple UNIX tools, and it doesn’t require any programming skills. This example will take about 15 minutes to complete. What you will use What You Need to Complete This Guide Install and configure the following separately before proceeding: Let’s Go! The code for this example is available on github. git clone This example uses vagrant to setup and configure two Ubuntu hosts and install Docker.

Cheat Sheet : All Cheat Sheets in one page GitHub - Leo-G/DevopsWiki: A wiki of Devops Tools, Tutorials and Scripts