Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. In Linux, we use passwd to change password, but passwd requires input from stdin to get the new password. It is common case that we may want…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. 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…
Note: This post covers WordPress configuration or PHP tips. Most remain applicable to modern WordPress (6.x). See WordPress Developer Docs for current best practices. WordPress has a very rich set of plugins and a combination of them can make anti-spam in WordPress quite easy. Here is a list of plugins that can help prevent spammers…
Note: This post covers SSH/VNC remote access setup. Core SSH concepts remain valid. For modern remote desktop options, see Arch Wiki VNC or tools like RDP, NoMachine, or RustDesk. This article is an instruction of how to use https://www.systutorials.com/proxy-using-ssh-tunnel/ on a Windows machine. The mechanism is similar as the one in https://www.systutorials.com/proxy-using-ssh-tunnel/ with “Proxy listening…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. noip2 is a dynamic update client for No-IP to keep your current IP address synchronized with your No-IP domain, no matter whether the IP is dynamically requested…
The software in Nokia E71 already support POP3 and IMAP email box. But we may lead to install Nokia messaging and setting up account of Nokia messaging. Storing our emails in remote servers isn’t a secure way. And why not use IMAP directly if it is supported by the system software? How to set up…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. We use tomcat as the container used for instructions in the post. 1) Download the driver mysql-connector-java-*.*.*-bin.jar and put it into WEB-INF/lib/, and remember to restart tomcat….
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. I frequently run some commands/scripts on a batch of servers whose IPs are already collected in a file. I usually use a simple loop and call the…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. This is a simple tutorial for beginners to SSH to a Linux host. This is quite easy with the easy-to-use software freely available but the beginners need…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. How to find out Linux and Windows uptime is introduced in this post. Linux uptime Linux uptime can be easily found out by the uptime command: $…
Historical Reference: This post covers legacy iOS device tools (iPod Touch, early iPhone). Modern iOS devices use entirely different jailbreak and management methods. For current iOS information, see Apple iOS. How to jailbreak Apple iPod touch in Linux will be introduced in this article. We use Spirit to jailbreak iPod touch. Spirit[1] is an untethered…
How to Set Up Password-less SSH Login on Linux Automatic password-less SSH login is one of those things you’ll set up once and be grateful for every day after. There are two approaches: key-based authentication (recommended) and password-based with a helper tool. I’ll cover both, but key-based is the way to go whenever your environment…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. The heirloom mailx (or s-nail if you are using Ubuntu 18 or later or similar releases) command in Linux is still providing service for guys like me,…
Historical Reference: This post covers Xen virtualization from 2013. While Xen is still used in production (e.g., AWS EC2, Citrix Hypervisor), KVM has become the default hypervisor for most Linux distributions. For modern virtualization, see KVM documentation or container-based solutions like Docker and Kubernetes. A script for backing up file-backed Xen DomU is introduced in…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. Sometimes we need to have the GUI of some application on the remote server. ssh’s X11 forwarding with “-X” parameter is a good and fast method. But…
Note: This post covers Linux fundamentals. Core concepts remain valid, but some commands and package names may differ on modern distributions. See your distro’s documentation for current details. How to configure NetworkManager to connect to sMobileNet in HKUST is introduced in this post. The wireless network connection configuration for sMobileNet in NetworkManager The SSID is…
Archived Content: This post covers Hadoop 0.x/1.x which is no longer maintained. Modern Hadoop 3.x+ includes significant improvements in YARN resource management, HDFS federation, and erasure coding. For new deployments, consider current Hadoop documentation or cloud-native alternatives like AWS EMR, Google Dataproc, or Azure HDInsight. Update: If you are new to Hadoop and trying to…
Note: This post covers Git basics or gitolite/gitosis setup. Core Git commands remain valid. For modern Git workflow tools, see Git documentation or hosted solutions like GitHub, GitLab. Update: Since gitosis is not maintained and supported, please check out gitolite for setting up a new git server. (see the comment from Sitaram Chamarty, the gitolite…