Here is the list of my general command line commands that I use in my experience.
\nDisplay path to current working place.
\npwd\nGo to a folder_name directory.
cd folder_name\nGo to parent directory.
\ncd ..\nFormatted list of files and folders in a directory.
\n-l - shows all files and folders like a list
ls -l\nFormatted list with all files and folders including hidden types of files.
\n-l - shows all files and folders like a list
\n-a - shows all hidden files and folders
ls -la\nCreated the new directory with name folder_name.
mkdir folder_name\nDelete the file file_name.
rm file_name\nDelete the directory folder_name with its subdirectories and files.
\n-r - delete all directories recursively
\n-f - force-delete files
rm -rf folder_name\nRename the file from old_file_name to new_old_file_name.
mv old_file_name new_old_file_name\nCopy the file file_name to the directory folder_name.
cp file_name folder_name\nCopy the directory source_folder_name with its subdirectories to the directory target_folder_name.
\n-r - copy a directory including all its content
cp -r source_folder_name target_folder_name\nClean a big log file path_to_log_file
cp /dev/null path_to_log_file\nChange permission of the file file_name to code 755
chmod 755 file_name\nChange permission of the directory folder_name to code 755 including its subdirectories.
\n-R - change permission recursively for all subdirectories
chmod -R 755 folder_name\nChange ownership of the file file_name to user user_name and to the group group_name
chown user_name:group_name file_name\nChange ownership of the directory folder_name to user user_name and to the group group_name
\n-R - change ownership recursively for all subdirectories
chown -R user_name:group_name folder_name\nClear command line interface.
\nclear\nShow the content of the file with the name file_name.
cat file_name\nCheck the information of disk usage of files and directories on a system.
\n-s - display only total space
\n-h - display in human-readable format
# Check space in root directory\ndu -sh /* \n# Check space in 'some_folder' directory\ndu -sh /some_folder/*\nKill process with the id process_id
kill process_id\nKill a process on the port port_value (example: 8080)
sudo kill -9 $(sudo lsof -t -i:port_value)\n# or\nsudo fuser -k port_value/tcp\nRestart Apache
\nsudo service apache2 restart\nRestart MySQL
\nsudo /etc/init.d/mysql restart\n