- Installed ubuntu 64bit 20.04.4 in virtualbox.
- pwd :- print the working directory.
- ls :- to list the items in current directory.
- --help :- to get help/manual.
- cd :- to enter into a particular directory.
- cd .. :- to go back one directory.
- ls -a :- for detailed list.
- mkdir dirname :- to create a dir.
- rmdir dirname :- to delete dir.
- touch filename.ext :- to create a file.
- rm filename.ext :- to delete that file.
- ls -l :- to print the permissions of the file.
- chmod ijk filename.ext :- to change admin , group , public permissions of file. (read, write and execute).