All About Linux.

When a file or directory needs different access, the task is to change its permissions without opening it up more than intended. chmod changes the rules that control access to files and directories. I’ll show how to set permissions with a number such as 640 or a letter-based change such as u+x, then check the

Terminal output can be useful to review alongside the commands that produced it. The Linux script command records an interactive terminal session in a file called a typescript, which contains entered commands and visible results. I’ll show you how to record and replay a session, and how to check its log for private input. TL;DR:

To schedule a Linux command for one future run, use at. The at utility queues a shell command as a job for the atd scheduler service to run once at a later time. I’ll explain what at does and show how to schedule a one-time job. TL;DR: Schedule a one-time Linux command The at command

A command can finish without showing how long it took. The Linux time command reports a command’s elapsed duration and CPU time. I’ll show how to time a command and choose the right time implementation for its summary. TL;DR: Time a Linux Command Prefix a command with time to measure it, and use /usr/bin/time when

A Linux machine may need to reach a service on another host, and a port check can show whether a TCP connection gets through. The telnet command attempts that connection and lets you interact with the endpoint. I’ll explain how to run the check and how to interpret its response. TL;DR The telnet command opens

Choosing a Linux desktop means deciding how its menus, panels and controls should fit the way you work. A desktop environment provides those on-screen parts, including menus, panels and settings tools. This piece helps you choose a desktop that fits your workflow and check whether your distribution supports it. TL;DR: Which Linux desktop should you

A Linux machine can show little free RAM when you are checking whether another application has room to run. Linux memory management assigns physical pages to processes and cached file data as demand changes. This article shows how to compare MemFree with MemAvailable and use vmstat to check for active paging. TL;DR: Read Available Memory

A service that will not accept a connection can leave you checking which ports Linux is listening on. netstat shows network connections and listening ports, while nslookup queries DNS records for a hostname. This article shows how to inspect listening ports with netstat and ss, then check a hostname’s DNS answer with nslookup. TL;DR Use

A Linux account may need access to a shared directory or device that is controlled by a group. The usermod command adds an existing account to a supplementary group, an additional membership that does not change its primary group. I’ll show how to add an account to one or more groups and check its membership