Linux Commands
Command references for core Linux tools, syntax, examples, and practical one-liners.
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.
ss Command in Linux: Display Socket Statistics
Use the ss command to list TCP, UDP, and Unix sockets, filter by port and state, read queue columns, inspect timers, and replace common netstat commands.
dnf Command in Linux: Install, Update, and Manage Packages
Common dnf commands for installing, updating, removing, searching, and managing packages on Fedora, RHEL, Rocky Linux, AlmaLinux, and other RPM-based systems.
wc Command in Linux: Count Lines, Words, and Bytes
The wc command counts lines, words, characters, and bytes in files or standard input. This guide covers common options with practical pipeline examples.
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.
Linux Kill Process: Stop Processes by PID or Name
Stop stuck programs in Linux with kill, killall, pkill, and xkill. Find the PID, send SIGTERM first, and use SIGKILL only when the process refuses to exit.
df Command in Linux: Check Disk Space Usage
Check disk space usage in Linux with the df command. Human-readable and fixed block sizes, filesystem types, inode usage, custom output fields, and df vs du.
How to Add a Directory to PATH in Linux
Add a directory to the PATH variable in Linux, temporarily or permanently, covering ~/.local/bin, custom binaries, and system-wide changes for all users.
traceroute Command in Linux
Trace the path packets take to a host, read every field of the traceroute output, decode hops that show asterisks or !X, and map Windows tracert flags to Linux.
Grep Regex: Regular Expressions Syntax and Examples
Use grep regex to match text patterns. Examples for anchors, character classes, quantifiers, alternation, grouping, and PCRE lookarounds.
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.
