SSH is a very common tool for Linux/Unix platforms. One annoying problem when using SSH is that the connection may get disconnected if the SSH connection is idle for some time under common configurations. Users may run an infinite loop like while true; do uptime; sleep 30; done when there is no work to be…
Port forwarding (or tunnelling) is a method to forward one network traffic to another. We will introduce how to forward ports using SSH tunnel in this post. A simple example Let’s start with a simple and useful example: we want to forward local port 8080 to server:port. We can easily do this by using ssh…
UDP has its advantages over TCP, such as being relatively lightweight and receiving one packet per read call (recvmsg), although the programmers need to handle related issues, such as packet lost and out-of-order packets delivery. This post gives information and references on how to write UDP programs in a C/Linux environment. What is UDP Check…
For UNIX users/developers, having the power of the user 0 (root’s UID) on our hands is essential. It also allows us to have complete control over the system. And one more thing we all have in common is that we hate Windows. Thus, we set out in search of an operating system for our own…
The socks proxy I created following Proxy Using SSH Tunnel works very well on both Linux and Windows. However, when I try to configure my iPhone and iPad with iOS, I find iOS does not support socks proxy in its settings interface. I don’t know why it is not added while socks proxy is indeed…
Symbolic link or soft link files are very common and useful on Linux/Unix systems. It works as a alias file for a file. You can create a symbolic links and it can operate transparently for most operations just as normal files. Programs that read or write to files named by a symbolic link behaves as…
Make is a utility that automatically builds executable programs and libraries from source code by reading files called makefiles which specify how to derive the target program. Make is widely used, especially in Unix/Linux world. More introductions to Make and it’s history can be found on Wikipedia. In this post, I list articles for Makefile…
One cool feature of gcc is that it can inline assembly into C code. With inline assembly, the programmer can precisely control the execution of the processor, such as forcing variables to use registers, getting special processor state efficiently, and writing critical efficient code in assembly by hand. I compile a list of tutorials from…
“The C language provides no built-in facilities for performing such common operations as input/output, memory management, string manipulation, and the like. Instead, these facilities are defined in a standard library, which you compile and link with your programs. The GNU C library, described in this document, defines all of the library functions that are specified…
This post compiles a list of tutorials on the Internet for Linux beginners. Linux beginners usually get headache from the “seemed” complexity of the Linux operation system. But once they get into the gate and get familiar with Linux, they will love it. UNIX Tutorial for Beginners “A beginners guide to the Unix and Linux…
ns is a discrete-event network simulator targeted primarily for research and educational use. There are two version of ns, ns-2 and ns-3, which are quite different with each other in the implementation and method to use them. In this post, we introduce how to install ns-2 and ns-3 on Fedora Linux 15. Install ns-2.34 on…
This is a introduction to *nix’s process management tools: pkill and pgrep. As this site’s domain name was pkill.info, a introduction to pkill should exist here. NAME pgrep, pkill – look up or signal processes based on name and other attributes SYNOPSIS pgrep [-flvx] [-d delimiter] [-n|-o] [-P ppid,…] [-g pgrp,…] [-s sid,…] [-u euid,…]…
How to set date, time and timezone on Linux/Unix box will be introduced in this post. Unix time, or POSIX time which is a system for describing points in time is the number of seconds elapsed since midnight UTC on the morning of January 1, 1970, not counting leap seconds. The number of seconds elapsed…
Linux port forwarding is simple to do with iptables which may probably already being used as the firewall or part of the setting up a Linux gateway. In the Linux kernel, port forwarding is achieved by packet filter rules in iptables. Port forwarding Port forwarding also called “port mapping” commonly refers to the network address…
We can set up a socks proxy on top of a SSH tunnel. Besides the common proxy functions, such as web browsing, the proxy on top of SSH tunnel also ensures the security between the browser and the proxy server (the SSH server). In this post, we introduce and explain how to set up a…
Using rpmfusion’s rpm packages to install NVIDIA driver in Fedora is introduced in this post. First, check the proper drivers for the card on [1]. 1. Add rpmfusion. Enable RPM Fusion repositories 2. Install the driver # yum install kmod-nvidia xorg-x11-drv-nvidia The reboot system. 3. Edit /etc/X11/xorg.conf # nvidia-xconfig The nouveau module conflicts with the…