Linux Commands
Command references for core Linux tools, syntax, examples, and practical one-liners.
How to Check if a Command Exists in Bash
Check whether a command exists in Bash with command -v, capture its path, validate several dependencies, and compare type, hash, and which.
setuid, setgid, and the Sticky Bit Explained
Understand the setuid, setgid, and sticky bit special permissions in Linux: what each one does on files and directories, how to set them, and the security risks.
How to Rename Files and Directories in Linux
Rename files and directories in Linux using mv for single renames and rename for batch filename changes, including extension changes, case conversion, and safe previews.
modprobe Command in Linux: Load and Manage Kernel Modules
Manage Linux kernel modules with modprobe: load, unload, blacklist, and configure module parameters. Includes syntax, practical examples, and troubleshooting.
curl vs wget: Differences and When to Use Each
Compare curl vs wget defaults, protocols, redirects, recursive downloads, API requests, and resume options to choose the right command for each task.
/etc/passwd in Linux: File Format and Fields Explained
The cat /etc/passwd command displays local Linux accounts. This guide explains its seven fields and when to use getent passwd instead.
at Command in Linux: Schedule One-Time Tasks
The at command schedules one-time tasks to run at a specific time in Linux. This guide covers syntax, time formats, batch jobs, listing and removing jobs, and user restrictions.
Bash Subshells: Isolate Variables and Directory Changes
Bash subshells run commands in an isolated shell environment. This guide explains parentheses, variable scope, directory changes, command substitution, pipelines, and exit codes.
hostnamectl Command in Linux: Set and Query Hostname
Use hostnamectl to view and change the Linux hostname. Covers static, transient, and pretty names, system metadata, remote hosts, and common errors.
host Command in Linux: DNS Lookup
The host command is a simple DNS lookup tool. This guide covers forward and reverse lookups, querying specific record types, using a chosen name server, and reading the output.
pidof Command in Linux: Find Process IDs by Name
The pidof command finds the process ID (PID) of a running program by name. This guide explains how to use pidof, its options, and how to pair it with kill to manage processes.
Linux Pipes Explained: How to Use the | Operator
Linux pipes connect command output to another command's input. Learn the | operator, pipefail, stderr piping, xargs, named pipes, and process substitution.
Linux Time Command
This guide shows how to use the Linux time command to measure execution time, explains real/user/sys, and covers Bash, Zsh, and GNU time.
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.
pnpm Command: Install and Manage Node.js Packages
This pnpm command guide covers installation, project setup, dependency management, scripts, lockfiles, npm migration, and workspace filtering.
ls Command in Linux: List Files and Directories
The ls command lists files and directories in Linux. See how to use ls -l, ls -al, hidden-file options, sorting, and other practical combinations.
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.
