Linux Commands
Command references for core Linux tools, syntax, examples, and practical one-liners.
Fix "No Space Left on Device" When df Shows Free Space
Fix Linux no-space errors when df shows free space by checking the target mount, inode usage, tmpfs limits, container storage, Btrfs, and inotify watches.
How to Add a User to a Group in Linux
Add users to Linux groups with usermod, verify group membership, change primary groups, and fix common issues when group changes do not apply.
pwd Command in Linux: Print the Current Working Directory
The pwd command prints the current working directory in Linux. This guide covers pwd syntax, the -L and -P options, $PWD and $(pwd) in scripts, and how symlinks affect the output.
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.
How to Create Users in Linux (useradd Command)
Create user accounts in Linux with useradd: home directories, passwords, groups, shells, UIDs, and expiry dates, plus how useradd compares to adduser.
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.
How to Install and Use uv: Fast Python Package Manager
Install uv on Ubuntu, Debian, and other Linux distributions, then use it to create projects, add dependencies, manage virtual environments, and install Python versions.
vmstat Command in Linux: Memory, CPU, and I/O Statistics
Use vmstat to monitor Linux CPU, memory, swap, processes, and disk I/O. This guide explains each column, live sampling, timestamps, and disk statistics.
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.
lsmod Command in Linux: List Kernel Modules
Display all currently loaded Linux kernel modules with lsmod. This guide covers output format, filtering, and related module management commands.
How to Remove (Delete) Files and Directories in Linux
Delete files and directories in Linux with rm, rmdir, unlink, and shred, plus bulk removal with find, safer confirmation prompts, and recoverable deletion.
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.
btop Command in Linux: Monitor System Resources
Monitor CPU, memory, disks, network traffic, and processes with btop. This guide covers installation, keyboard shortcuts, process actions, and configuration.
Listing Linux Services with systemctl
Use the systemctl command to list running, failed, and enabled Linux services. Includes filtering by state, checking status, and listing unit files.
CPU Info on Linux: Check CPU Details from the Command Line
Read CPU model, core and thread counts, cache sizes, and virtualization support on Linux from the command line with /proc/cpuinfo, lscpu, and dmidecode.
ps Command in Linux: ps aux and Common Options
Use ps aux and related ps command options in Linux to list running processes, read output columns, sort by CPU or memory, filter by PID or user, and show full command lines.
Check Open Ports in Linux: nmap, netcat, and Bash
Scan a Linux host or remote server for open ports with nmap, netcat, telnet, and Bash /dev/tcp, then distinguish closed ports from filtered connections.
