Clear Command (with examples)
The “clear” command is used to clear the screen of the terminal. It provides a simple and convenient way to remove the clutter from the terminal window without closing and reopening the terminal.
Use Case 1: Clearing the screen
Code:
clear
Motivation:
The “clear” command is particularly useful when the terminal screen is cluttered with previous command outputs or logs, making it difficult to read new content. By using this command, the screen can be cleared to start with a fresh, clean view.
Explanation:
Executing the “clear” command without any arguments clears the terminal screen. It is equivalent to pressing Control-L (or ^L) in the Bash shell.
Example Output:
[Previous terminal content is cleared and the screen is empty]
Use Case 2: Clearing the screen but keeping the scrollback buffer
Code:
clear -x
Motivation:
In some cases, you may want to clear the screen but retain the scrollback buffer. This allows you to preserve the history of previous commands and outputs for reference, while still keeping the current view clean and uncluttered.
Explanation:
Adding the “-x” option to the “clear” command clears the terminal screen while preserving the scrollback buffer. The scrollback buffer stores the previous terminal output, which can be accessed by scrolling up or using the “Page Up” key.
Example Output:
[Previous terminal content is cleared, but scrolling back shows the history of previous commands and outputs]
Use Case 3: Clearing the screen for a specific terminal type
Code:
clear -T type_of_terminal
Motivation:
The terminal type is an important factor in determining the behavior of various terminal commands. In some cases, different terminal types might require specific handling or clearing procedures. By specifying the terminal type explicitly, you can ensure that the “clear” command behaves correctly for the given terminal.
Explanation:
The “-T” option followed by the desired terminal type allows you to indicate the specific terminal type to clean. By default, the command uses the value of the environment variable “TERM” to determine the terminal type.
Example Output:
[Terminal screen of the specified terminal type is cleared]
Use Case 4: Checking the version of ncurses library used by “clear”
Code:
clear -V
Motivation:
The “clear” command relies on the underlying ncurses library to perform its functionality. By checking the version of ncurses used by “clear”, you can ensure that you have the latest version installed and take advantage of any bug fixes or improvements.
Explanation:
By adding the “-V” option to the “clear” command, it displays the version of the ncurses library being used.
Example Output:
ncurses version 6.2
