Linux

7 Practical Linux Locate Command Examples – mlocate and updatedb

by Himanshu Arora on March 14, 2012

When you need to search for some files, you might typically use find command. find is a good search utility but it is slow. However locate can search for files very quickly. Though the locate command works very fast, it still has not out-thrown the find command because it has some limitations. This article explains [...]

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Linux Processes – Environment extern, environ, getenv, setenv

by Himanshu Arora on March 12, 2012

This is the 1st article of a new series on the processes in Linux. The focus of this series would be on the practical aspects of process environment, process control, process relationships etc. In this article, we will discuss how to get and set environment variables inside a C program. Linux Processes Series: part 1 [...]

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Linux Signals – Example C Program to Catch Signals (SIGINT, SIGKILL, SIGSTOP, etc.)

by Himanshu Arora on March 9, 2012

In the part 1 of the Linux Signals series, we learned about the fundamental concepts behind Linux signals. Building on the previous part, in this article we will learn about how to catch signals in a process. We will present the practical aspect of signal handling using C program code snippets. Catching a Signal As [...]

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Reverse Engineering Tools in Linux – strings, nm, ltrace, strace, LD_PRELOAD

by Lakshmanan Ganapathy on March 7, 2012

This article explains about the tools and commands that can be used to reverse engineer an executable in a Linux environment. Reverse engineering is the act of figuring out what a software does, to which there is no source code available. Reverse engineering may not give you the exact details of the software. But you [...]

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Linux Signals Fundamentals – Part I

by Himanshu Arora on March 5, 2012

What is a signal? Signals are software interrupts. A robust program need to handle signals. This is because signals are a way to deliver asynchronous events to the application. A user hitting ctrl+c, a process sending a signal to kill another process etc are all such cases where a process needs to do signal handling. [...]

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10 Practical Linux nm Command Examples

by Himanshu Arora on March 2, 2012

The nm commands provides information on the symbols being used in an object file or executable file. The default information that the ‘nm’ command provides is : Virtual address of the symbol A character which depicts the symbol type. If the character is in lower case then the symbol is local but if the character [...]

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10 Linux DIG Command Examples for DNS Lookup

by Ramesh Natarajan on February 29, 2012

Dig stands for domain information groper. Using dig command you can query DNS name servers for your DNS lookup related tasks. This article explains 10 examples on how to use dig command. 1. Simple dig Command Usage (Understand dig Output) When you pass a domain name to the dig command, by default it displays the [...]

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Linux Memory Management – Swapping, Caches and Shared VM

by Himanshu Arora on February 27, 2012

This article is part of our on-going UNIX kernel overview series. In the previous article of the kernel series, we discussed about Linux virtual memory and demand paging. Though virtual memory and demand paging are the building blocks of the Linux memory management system, there are various other concepts that make Linux memory management very [...]

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