Moving files between directories or machines calls for a way to copy them while keeping their directory structure. rsync is a file-copying utility that works locally or across a network and can synchronize a destination with a source. In this piece, I’ll walk through copying a directory locally or over SSH and previewing the planned
Rsync Command in Linux: Copy and Sync Files Read More »
Choosing a package source can be confusing when Debian offers its own route and Oracle publishes another. VirtualBox runs virtual machines, and its host package can come from Oracle’s APT repository or Debian Fast Track. I’ll explain how those package sources differ and walk through installing VirtualBox from Oracle’s repository on a supported release. TL;DR:
Install VirtualBox on Debian: Oracle APT Guide Read More »
Scripts sometimes need to run the same task with different input. A Bash function names a group of commands and accepts arguments when the script calls it. I’ll walk through passing arguments to functions and choosing between a status and printed data for results. TL;DR A Bash function gives a name to commands you can
Shell Script Functions: Define and Use Them Read More »
Some projects include their own Gradle launcher, while you may also need a Gradle command in your shell for work outside that project. Gradle is a build automation tool that reads a project’s build definition and runs tasks such as compiling or testing code. This guide shows how to choose between a project’s Wrapper and
How to Install Gradle on Ubuntu and Debian Read More »
Setting up Java on Linux means choosing the installation directory a program should use. JAVA_HOME is an environment variable that names that Java installation directory. I’ll show you how to find the JDK root and set JAVA_HOME for the shell or system that runs your program. TL;DR: Set JAVA_HOME to the JDK directory Set JAVA_HOME
How to Set the JAVA_HOME Variable in Linux Read More »
Sometimes a program keeps running after its work is done, and you need to stop it without looking up a process ID. The PSmisc version of killall selects running programs by command name and sends them a signal, with SIGTERM as its default. In this piece, I’ll show you how to check your installed implementation
Linux killall Command: How to Stop Processes by Name Read More »
Managing a Debian or Ubuntu server from a browser calls for an administration tool that runs on the server. Webmin provides that interface, which you access through a browser. I’ll show how to install Webmin from its APT repository and connect to its HTTPS interface. TL;DR Use Webmin’s setup script to configure its APT repository
How to Install Webmin on Debian and Ubuntu Read More »
Linux password rules can be stored in different places, depending on whether they check a new password or control when an account password expires. A Linux password policy combines password-quality checks with account settings that determine when passwords expire. I’ll show how to inspect the active PAM password stack and read an account’s aging settings
Linux Password Policy: Configure PAM Rules Read More »
Running a Java program requires a runtime, while building one also requires a compiler. Debian provides OpenJDK packages through APT, including a runtime and a development kit. This article shows how to check which Java packages your Debian repositories offer and choose the JDK or runtime package to install. TL;DR Install Debian’s default Java development
How to Install Java on Debian Read More »
At the prompt, a script may receive a value typed by the user or capture output from a command. A shell variable gives that value a name the script can use later. In this piece, I’ll show how to assign and use Bash variables, including passing a value to a child process. TL;DR In Bash,
Shell Script Variables: Assign and Use Them Read More »