Linux Commands
Command references for core Linux tools, syntax, examples, and practical one-liners.
Uptime Command in Linux
The uptime command shows how long a Linux system has been running, the number of logged-in users, and the load averages for the last 1, 5, and 15 minutes.
npm Command: Install and Manage Node.js Packages
This npm command guide covers project setup, local and global package installs, npm ci, updates, dependency removal, scripts, and one-off package runs.
Fix "sudo: command not found" on Linux
How to fix the 'sudo: command not found' error on Linux by installing the sudo package, adding your user to the right group, and recovering from a broken PATH.
chgrp Command in Linux: Change File Group Ownership
The chgrp command changes the group ownership of files and directories in Linux. This guide covers syntax, recursive changes, symlink handling, and practical examples.
dpkg Command in Linux: Install and Manage Debian Packages
Use dpkg to install, remove, query, and inspect Debian packages on Ubuntu, Debian, and other Debian-based distributions.
tr Command in Linux: Translate, Delete, and Squeeze Characters
The tr command translates, deletes, and squeezes characters from standard input. This guide covers tr syntax, character sets and ranges, case conversion, removing line endings, and practical pipeline examples.
iptables Command in Linux: Manage Firewall Rules
Manage Linux firewall rules with iptables. This guide covers tables and chains, listing rules, allowing and blocking ports and IP addresses, setting default policies, and saving rules across reboots.
ripgrep Command in Linux: Fast Recursive Search
The ripgrep command searches directories recursively while respecting ignore files. This guide explains rg syntax, file type filters, context lines, replacement previews, and config defaults.
nslookup Command in Linux: Query DNS Records
The nslookup command queries DNS servers for domain records. This guide covers A, MX, NS, TXT, and AAAA lookups, reverse DNS, interactive mode, and choosing a specific name server.
whois Command in Linux: Query Domain Registration Info
The whois command looks up domain registration, registrar, name server, expiry, IP allocation, and AS number details from Linux.
Bash Arithmetic: Integer and Floating-Point Math
How to do arithmetic in Bash with the (( )) operator, $(( )) expansion, the let builtin, and bc or awk for floating-point math the shell cannot do natively.
How to Format USB Drives and SD Cards on Linux
Step-by-step instructions for formatting USB drives and SD cards on Linux using parted and mkfs. Covers FAT32, exFAT, EXT4, and NTFS filesystems with partition table setup and verification.
rsync Exclude Patterns: Skip Files and Directories
Exclude files and directories from an rsync transfer with --exclude and --exclude-from, glob patterns, and dry-run previews, with copy-paste examples.
How to Use the kill Command in Linux
Learn how to use the kill command in Linux to terminate processes, send signals, and reload services with practical examples.
How to Install Podman on Ubuntu: Rootless Container Alternative to Docker
Step-by-step instructions for installing Podman on Ubuntu, running rootless containers, building images with Buildah, and switching from Docker.
nmcli Command in Linux: NetworkManager CLI Reference
The nmcli command manages NetworkManager from the terminal. This guide covers device status, Wi-Fi connections, static IP configuration, DNS settings, and scripting-friendly output.
timedatectl Command in Linux: Manage Time, Date, and Time Zone
Use timedatectl to check system time, change the time zone, control NTP synchronization, set the clock manually, and inspect RTC settings on Linux.
How to Check CPU Usage in Linux
This guide explains how to check CPU usage in Linux with top, htop, mpstat, vmstat, sar, ps, uptime, and per-core load tools.
systemctl Command in Linux: Start, Stop, and Manage Services
Manage services on systemd-based Linux distributions with systemctl. This guide explains how to start, stop, restart, enable, and disable services, reload unit files, and inspect service status.
How to Use the pkill Command in Linux
The pkill command sends signals to Linux processes by name, user, terminal, or full command pattern. Covers safe matching, common options, and examples.
