Bash Cheatsheet

Bash is a shell scripting language that is used to automate repetitive tasks. The following are commonly used bash commands.

SSH Commands

• ssh {user}@{host} - SSH into a remote host using a password.
• ssh -i {keyfile} {user}@{host} - SSH into a remote host using a private key.

Filesystem Commands

• pwd - Prints the current working directory.
• ls - Lists the contents of the current directory.
• cd - Changes the current working directory.
• mkdir - Creates a directory.
• touch - Creates a file.
• rm - Removes a file or directory.
• cp - Copies a file or directory.
• mv - Moves a file or directory.
• cat - Displays the contents of a file.
• grep - Searches for a string in a file.
• head - Displays the first few lines of a file.
• tail - Displays the last few lines of a file.
• less - Displays the contents of a file in a pager.
• more - Displays the contents of a file in a pager.

Text Processing Commands

• nano - A text editor.
• vim - A text editor.
• vi - A text editor.

Permissions

• chmod - Changes the permissions of a file or directory.
• chown - Changes the owner of a file or directory.
• sudo - Runs a command as the super user.
• su - Runs a command as another user.

Resource Management

• top - Shows the processes running on the node.
• htop - Interactive version of top.
• kill {pid} - Kills a process by its PID.
• kill -KILL {pid} - Forcefully kill a process.
• killall -9 {name} - Kills all processes by name.
• skill -KILL -u {user} - Kills all processes owned by a user and logs them out.
• pkill -KILL -u {user} {process} - Kills all processes owned by a user.

User Management

• w or who - Shows users logged in to the host.
• whoami - Shows the current user.
• ps -fu {user} - See running processes for a user.
• passwd {user} - Set the password for a user.
• cat /etc/passwd - List users on the system.
• sudo usermod -l {new_login_name} {old_login_name} - Change the user's login name.
• usermod -d {new_home_directory_path} username - Change the user's home directory.
• userdel -r {username} - Delete a user.

Networking

• curl - Makes a HTTP request.

Miscellaneous

• man {topic} - Opens the manual for a topic.