Linux Commands Cheat Sheet#

1. File and Directory Management#

• ls
  List files and directories.
  Example:

  ls
  

• ls -l
  List files with detailed information.
  Example:

  ls -l
  

• mkdir
  Create a new directory.
  Example:

  mkdir new_folder
  

• rmdir
  Remove an empty directory.
  Example:

  rmdir empty_folder
  

• rm
  Delete files or directories.
  Example:

  rm file.txt
  

• cp
  Copy files or directories.
  Example:

  cp source.txt destination.txt
  

• mv
  Move or rename files.
  Example:

  mv old_name.txt new_name.txt
  

• pwd
  Show the current directory.
  Example:

  pwd
  

2. File Viewing#

• cat
  Display file contents.
  Example:

  cat file.txt
  

• less
  View file with pagination.
  Example:

  less file.txt
  

• head
  Display the first 10 lines of a file.
  Example:

  head file.txt
  

• tail
  Display the last 10 lines of a file.
  Example:

  tail file.txt
  

• tail -f
  Follow updates to a file (e.g., log file).
  Example:

  tail -f log.txt
  

3. File Permissions and Ownership#

• chmod
  Change file permissions.
  Example:

  chmod 755 script.sh
  

• chown
  Change file ownership.
  Example:

  chown user:group file.txt
  

• ls -l
  View file permissions and ownership.
  Example:

  ls -l
  

4. Searching#

• grep
  Search for a pattern in a file.
  Example:

  grep "search_term" file.txt
  

• grep -r
  Search recursively in directories.
  Example:

  grep -r "search_term" directory/
  

• find
  Locate files by name or criteria.
  Example:

  find /path -name "file.txt"
  

• locate
  Search files quickly using a pre-built database.
  Example:

  locate file.txt
  

• updatedb
  Update the database for locate.
  Example:

  sudo updatedb
  

5. Disk Usage#

• df -h
  Show free disk space in human-readable format.
  Example:

  df -h
  

• du -h
  Show disk usage of files/directories.
  Example:

  du -h directory/
  

6. Networking#

• ip addr
  Display network interfaces and IP addresses.
  Example:

  ip addr
  

• ping
  Test connectivity to a host.
  Example:

  ping google.com
  

• netstat
  View network connections.
  Example:

  netstat -tuln
  

• nslookup
  Query DNS records for a domain.
  Example:

  nslookup example.com
  

• traceroute
  Trace the route to a host.
  Example:

  traceroute google.com
  

7. User Management#

• adduser
  Add a new user.
  Example:

  sudo adduser username
  

• deluser
  Remove a user.
  Example:

  sudo deluser username
  

• whoami
  Show the current logged-in user.
  Example:

  whoami
  

• who
  Show logged-in users.
  Example:

  who
  

8. Process Management#

• ps aux
  List all running processes.
  Example:

  ps aux
  

• top
  Display real-time process usage.
  Example:

  top
  

• kill
  Terminate a process by PID.
  Example:

  kill 1234
  

• killall
  Terminate processes by name.
  Example:

  killall firefox
  

9. Package Management (Debian-based Systems)#

• apt update
  Update package lists.
  Example:

  sudo apt update
  

• apt upgrade
  Upgrade installed packages.
  Example:

  sudo apt upgrade
  

• apt install
  Install a package.
  Example:

  sudo apt install curl
  

• apt remove
  Remove a package.
  Example:

  sudo apt remove package_name
  

• apt search
  Search for a package.
  Example:

  apt search package_name
  

10. System Monitoring#

• uname -a
  Display system information.
  Example:

  uname -a
  

• free -h
  Show memory usage in human-readable format.
  Example:

  free -h
  

• uptime
  Show system uptime.
  Example:

  uptime
  

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