MANAGE DIRECTORIES
pwd: print name of current/working directory
ls: list directory contents
mkdir ‘directory name’: make directories
mkdir -p ‘directories names’: make parent directories as needed
rmdir: remove empty directory
rmdir -p ‘name of directories’: remove directory and its ancestors
rm -rf: remove a directory not empty
MANAGE FILES
file: determine file type
touch ‘file name’: change file timestamps. In case of file not existing, system will create an empty file
rm: remove files or directories
rm -i: prompt once before removing files
rm ‘*.file extension’: remove all files with the specified extension
rm ‘file1 file2 …’: remove files
cp: copy files and directories
mv: move (rename) file
head ‘file name’: output the first part of file (10 lines by default)
tail ‘file name’: output the last part of files (10 lines by default)
cat: concatenate files and print on the standard output
echo ‘text’: display a line of text
SYSTEM INFORMATION
uptime: tell how long the system has been running
free: display amount of free and used memory in the system
ps -e: report a snapshot of the current processes
df -h: report file system disk space usage
top: display Linux processes
htop: interactive process viewer
NETWORKING
ifconfig: configure a network interface
ping: send ICMP ECHO_REQUEST to network hosts
MISCELLANEOUS
sudo apt update: download package information from all configured sources
sudo apt upgrade: install the new packages
nano: editor
man: show the ‘Manual pages’ for Linux commands