Linux Command Cheat Sheet LINUX ADMIN MEGA REFERENCE Linux CommandCheat Sheet A massive searchable, copy-ready reference for Linux students, technicians, homelab users, and sysadmins. 382 commands 27 sections 1 standalone HTML file Expand All Collapse All ⚠ Admin warning: Commands marked with ⚠ can delete data, overwrite disks, or make major system changes. Verify device names and paths before running them. JUMP TO SECTIONNavigation & FilesViewing & Editing TextSearch & Text ProcessingPermissions & OwnershipUsers & GroupsProcesses & JobsSystem InformationDisks & FilesystemsNetworkingSsh & Remote AccessSystemd & ServicesLogs & TroubleshootingApt — Debian & UbuntuDnf & Rpm — Fedora/RhelPacman — ArchArchives & CompressionShell & EnvironmentRedirection & PipesDisk ImagingSchedulingFirewall BasicsDockerGitHardware & DevicesPerformanceUseful One-LinersHelp & Documentation Navigation & Files28 commands▾ pwdCOPY Print the current directory lsCOPY List files and directories ls -lahCOPY Detailed listing including hidden files and human-readable sizes ls -ltCOPY List newest files first ls -lSCOPY List largest files first cd /path/to/dirCOPY Change directory cd ..COPY Move up one directory cd ~COPY Go to your home directory cd -COPY Return to the previous directory treeCOPY Display directory contents as a tree touch file.txtCOPY Create an empty file or update its timestamp mkdir newdirCOPY Create a directory mkdir -p a/b/cCOPY Create nested directories cp file1 file2COPY Copy a file cp -r dir1 dir2COPY Copy a directory recursively cp -a source/ dest/COPY Copy while preserving metadata mv old newCOPY Move or rename a file or directory rm file.txtCOPY Delete a file rm -r directoryCOPY Delete a directory recursively ⚠ rmdir emptydirCOPY Remove an empty directory ln -s /target linknameCOPY Create a symbolic link readlink -f linknameCOPY Resolve a symbolic link file filenameCOPY Identify a file type stat filenameCOPY Show detailed file metadata find . -type fCOPY Find all files recursively find /var/log -name '*.log'COPY Find files by name find . -type f -size +100MCOPY Find files larger than 100 MB locate filenameCOPY Search the locate database Viewing & Editing Text16 commands▾ cat file.txtCOPY Print a file tac file.txtCOPY Print lines in reverse order less file.txtCOPY View a file page by page more file.txtCOPY Simple paged file viewer head file.txtCOPY Show the first 10 lines head -n 25 file.txtCOPY Show the first 25 lines tail file.txtCOPY Show the last 10 lines tail -f /var/log/syslogCOPY Follow a growing log file nano file.txtCOPY Edit with Nano vim file.txtCOPY Edit with Vim wc -l file.txtCOPY Count lines wc -w file.txtCOPY Count words nl file.txtCOPY Show line numbers column -t file.txtCOPY Align whitespace-separated columns strings binaryfileCOPY Extract printable strings from a binary xxd fileCOPY Hex dump a file Search & Text Processing20 commands▾ grep 'text' file.txtCOPY Search for text grep -i 'text' file.txtCOPY Case-insensitive search grep -R 'text' /pathCOPY Recursive search grep -n 'text' file.txtCOPY Show matching line numbers grep -v 'text' file.txtCOPY Show nonmatching lines grep -E 'catCOPY dog' file.txt|Extended regex search cut -d: -f1 /etc/passwdCOPY Extract the first colon-delimited field sort file.txtCOPY Sort lines alphabetically sort -n numbers.txtCOPY Sort numerically uniq file.txtCOPY Remove adjacent duplicates sort file.txtCOPY uniq -c|Count repeated lines tr 'a-z' 'A-Z' < file.txtCOPY Convert lowercase to uppercase sed 's/old/new/g' file.txtCOPY Replace text in output sed -i 's/old/new/g' file.txtCOPY Replace text in place awk '{print $1}' file.txtCOPY Print the first field awk -F: '{print $1}' /etc/passwdCOPY Print the first colon-delimited field paste file1 file2COPY Merge files side by side comm file1 file2COPY Compare two sorted files diff -u old.txt new.txtCOPY Show a unified diff xargs -n1 echo < file.txtCOPY Build command arguments from stdin Permissions & Ownership13 commands▾ ls -lCOPY Show Unix permissions and ownership chmod 644 file.txtCOPY Set rw-r–r– chmod 755 script.shCOPY Set rwxr-xr-x chmod +x script.shCOPY Add execute permission chmod -R 750 directoryCOPY Change permissions recursively chown user file.txtCOPY Change owner chown user:group file.txtCOPY Change owner and group chown -R user:group directoryCOPY Change ownership recursively chgrp group file.txtCOPY Change group ownership umaskCOPY Show current creation mask umask 022COPY Set a common creation mask getfacl file.txtCOPY Display ACL permissions setfacl -m u:alice:rw file.txtCOPY Grant ACL permissions to a user Users & Groups19 commands▾ whoamiCOPY Print current username idCOPY Show UID GID and groups id usernameCOPY Show another user's identity information whoCOPY Show logged-in users wCOPY Show logged-in users and activity lastCOPY Show login history usersCOPY Print logged-in usernames sudo commandCOPY Run a command with elevated privileges sudo -iCOPY Open a root login shell su – usernameCOPY Switch to another user useradd -m usernameCOPY Create a user and home directory adduser usernameCOPY Interactive user creation on Debian or Ubuntu passwd usernameCOPY Set or change a password usermod -aG sudo usernameCOPY Add a user to sudo group usermod -aG group usernameCOPY Add a user to a supplementary group groups usernameCOPY Show group memberships groupadd groupnameCOPY Create a group userdel -r usernameCOPY Delete a user and home directory ⚠ getent passwd usernameCOPY Query account information Processes & Jobs20 commands▾ psCOPY Show processes in the current shell ps auxCOPY Show all processes ps -efCOPY Show all processes in full format topCOPY Interactive process monitor htopCOPY Enhanced interactive process monitor pgrep nginxCOPY Find PIDs by name pidof sshdCOPY Print PID of a program kill PIDCOPY Send SIGTERM kill -9 PIDCOPY Force-kill with SIGKILL pkill nginxCOPY Kill processes by name killall processnameCOPY Kill all matching processes nice -n 10 commandCOPY Start with adjusted priority renice 5 -p PIDCOPY Change priority of a running process jobsCOPY List shell jobs command &COPY Run a command in the background fg %1COPY Bring job 1 to foreground bg %1COPY Resume job 1 in background nohup command &COPY Keep a command running after logout watch -n 2 commandCOPY Repeat a command every 2 seconds time commandCOPY Measure execution time System Information19 commands▾ uname -aCOPY Show kernel and architecture information uname -rCOPY Show kernel version hostnameCOPY Show hostname hostnamectlCOPY Show hostname and system metadata cat /etc/os-releaseCOPY Show Linux distribution information lsb_release -aCOPY Show distribution details if installed uptimeCOPY Show uptime and load averages dateCOPY Show current date and time timedatectlCOPY Show time configuration calCOPY Display a calendar archCOPY Show machine architecture lscpuCOPY Show CPU information free -hCOPY Show memory usage vmstatCOPY Show memory CPU and process