Linux shell prompt tips
Enter the command alone at a shell prompt and press [Enter]. For example, entering cp alone returns a brief description of the command and its usage.
Other commands, such as cat, require no arguments or files to run as normal. To quit such a command, press [Ctrl]-[D]. If that does not work, press [Ctrl]-[C].
Tips for the bash shell
Below are a few useful features of the bash shell that reduce the amount of typing required at a shell prompt. The first of these is tab completion, the second is command history, and the third is useful keystrokes.
Tab Completion
Tab completion is one of the most useful shortcuts available at the command line. Linux has the ability to "guess" what command, directory, or filename you are entering at the shell prompt. Press the [Tab] key, and the shell offers possible completions for partial words. The more letters typed before pressing [Tab], the closer the shell comes to the intended command.
If there are multiple solutions to the partial text on the command line, the shell presents them as a list. If the list is very long, the shell will first ask if you would like to display all matches. Navigate long lists of potential matches by pressing the [Space] bar to go down one page, the [B] key to go back one page, the directional (or "arrow") keys to move one line at a time, and [Q] to quit.
There are many number of symbols that can be used to indicate end of the shell eg "$" and "#".There is a slight difference between these sysmbols. Whenever the shell is ending with :$" i.e.,
The shell assumes that the first word entered at the prompt is a command. The possible completions it offers are the names of commands or applications. This can be helpful if you are not sure of the exact spelling of a command or if you are searching for a certain command. It can also serve to help a new user become familiar with the available commands.