# print working directory
$ pwd
# provide the help of command
$ man command_name
# locate the command/ return the path name
$ which command_name
# Listing
$ ls
$ ls -a # List hidden file
# Change Directory
$ cd ~ # Navigate to home directory
$ cd / # Navigate to root directory
$ cd - # Navigate to previus directory
# Move File - mv [file-name] [directory-name]
$ mv file-to-move directory/
# Copy File
$ cp file1 file2
# Remove file / directory
$ rm filename
$ rmdir dirname # Remove directory
# use apt-get to install the package
$ sudo apt-get install package_name
# remove package
$ sudo apt-get remove package_name
# Install .deb file
$ sudo dpkg -i pakage_file_name.deb
# grep - find string in file, can used regular expression
$ grep 'search_string' file_name
# services
$ service --status-all # list all services
$ service service_name start # start service
$ service service_name stop # stop service
$ sudo status service_name # check the service status
# Proccess
$ ps # display all running proccess