Linux Commands
Command references for core Linux tools, syntax, examples, and practical one-liners.
passwd Command in Linux: Change User Passwords
Change your own, another user's, or the root password in Linux with the passwd command. Covers password expiry with chage, forcing a change at next login, and account locking.
tree Command in Linux: Display Directory Structure
The tree command lists directories recursively as an indented tree. This guide covers installation, depth limits, filtering, sizes, and saving the output.
curl Command in Linux: Usage and Examples
The curl command transfers data to and from servers using HTTP, HTTPS, FTP, and other protocols. This guide covers downloads, headers, POST requests, verbose debugging, proxies, and API usage.
nohup Command in Linux: Background Jobs and Output
nohup keeps commands running after logout. The 'appending output to nohup.out' message is not an error. This guide covers background jobs, 2>&1 redirection, and stopping processes.
tmux Command in Linux: Sessions, Windows, and Panes
The tmux command lets you run persistent terminal sessions with multiple windows and panes. This guide covers creating and managing sessions, splitting panes, copy mode, and configuration.
strace Command in Linux: Trace System Calls
Use the strace command to trace system calls and signals on Linux, debug why a program fails, find missing files, and measure where a process spends its time.
How to Manage Node.js Processes with PM2
How to install PM2, run and manage Node.js processes with clustering, zero-downtime reloads, log rotation, and systemd integration that survives reboots.
htop Command in Linux: How to Monitor and Manage Processes
Monitor Linux processes in real time with htop: read CPU and memory meters, sort and filter the process list, and kill or renice processes from one screen.
smartctl Command in Linux: Check Disk Health with SMART
Use smartctl in Linux to check SMART health, read disk attributes, run self-tests, troubleshoot USB enclosures, and monitor NVMe wear.
find Command in Linux: Search Files and Directories
The find command searches for files and directories by name, type, size, date, permissions, and more. This guide covers practical examples including wildcards, exec actions, and combining find with grep.
How to Create a Directory in Linux: mkdir Command Examples
Create single, multiple, and nested directories in Linux with mkdir, set permissions with -m, and fix 'Permission denied' and 'No such file or directory' errors.
ffmpeg Command in Linux: Convert, Compress, and Extract Media
Practical ffmpeg examples for converting between formats, compressing video with CRF, extracting audio, trimming clips, resizing video, and batch processing files on Linux.
du Command in Linux: Check Disk Usage
The du command reports disk space used by files and directories. This guide covers human-readable output, summary totals, depth limiting, sorting by size, and practical examples.
head Command in Linux: Print the First N Lines of a File
The head command prints the first lines or bytes of a file. This guide shows how to display a specific number of lines, preview files, and limit command output in pipelines.
Linux Wildcards and Globbing Explained
How shell wildcards and globbing work in Linux: the *, ?, and [...] patterns, brace expansion, why globbing is not regex, and how to control it with quoting.
git diff Command: Compare Changes Between Commits and Branches
Use git diff to compare your working directory, staged files, commits, and branches, with practical examples of the options you will use most.
last Command in Linux: Check Login History
Use the last command in Linux to check login history, filter sessions by user or date, and audit system access. Also covers lastb for failed logins and lastlog for per-user login records.
