Linux Commands
Command references for core Linux tools, syntax, examples, and practical one-liners.
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.
reboot Command in Linux: Restart with systemctl and shutdown -r
Three commands cover common Linux reboot scenarios: reboot for an immediate restart, systemctl reboot for the systemd path, and shutdown -r for scheduled restarts with user notifications.
CPU Info on Linux: Check CPU Details from the Command Line
Two commands give you everything about your CPU on Linux: /proc/cpuinfo for raw per-core details, and lscpu for a readable summary. See how to use both.
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.
Understanding the /etc/fstab File in Linux
The /etc/fstab file defines how filesystems and storage devices are mounted at boot. This guide explains the fstab format, field meanings, mount options, and how to add new entries safely.
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.
rm Command in Linux: Remove Files and Directories
Use the rm command in Linux to delete files and directories, with examples for recursive removal, force mode, prompts, glob patterns, and safer rm -rf usage.
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.
How to Run Linux Commands in the Background
Run Linux commands in the background using &, disown, and nohup. This guide explains how to start background processes, move foreground jobs to the background, and keep processes running after the shell exits.
How to Add a Directory to PATH in Linux
How to add a directory to the PATH variable in Linux for the current session or permanently, covering user-level and system-wide methods.
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.
Linux cp Command: Copy Files and Directories
The cp command copies files and directories in Linux. This guide covers recursive and archive copies, overwrite controls, preserving attributes, and practical examples.
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.
Sudo Command in Linux: Run Commands as Root
A complete guide to the Linux sudo command. Learn how to run commands as root, manage sudoers, open a root shell, list privileges, set timeouts, and more.
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.
