Signals & Control
Cancel commands, send EOF, suspend processes, and clear the screen with Ctrl shortcuts.
Sometimes you need to interrupt what the terminal is doing. Maybe a command is running longer than expected, you want to cancel what you're typing, or you just want a clean screen. The terminal has a set of control shortcuts that act as emergency buttons.
Ctrl+C Cancel the current command or running process
Ctrl+D Send EOF (End of File) — closes the shell if the line is empty
Ctrl+Z Suspend the current process (move it to background)
Ctrl+L Clear the screen (same as typing 'clear')Ctrl+C is your most important escape hatch. If a command is running too long, producing endless output, or you just changed your mind, Ctrl+C sends an interrupt signal that stops the process immediately. You can also use it to clear a partially typed command without running it.
Ctrl+D sends an "end of file" signal. If your command line is empty, it will close your terminal session (like typing
exit). If a program is waiting for input (like cat with no arguments), Ctrl+D tells it you're done providing input.Ctrl+Z suspends a running process and puts it in the background. The process isn't killed — it's paused. You can resume it with the
fg command (foreground) or let it run in the background with bg. This is useful when you're in the middle of something (like editing a file with nano) and need to quickly run another command.Ctrl+L clears the screen without erasing your command history. It's identical to running
clear, but faster since you don't have to type anything. Many developers press Ctrl+L habitually before running important commands so the output is easy to read.●
Ctrl+C and Ctrl+L are the two most-used control shortcuts. Commit them to muscle memory first. Ctrl+C = "stop everything" and Ctrl+L = "clean slate."
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Be careful with Ctrl+D on an empty prompt — it will close your terminal session. If you accidentally start closing a shell, most terminals will warn you or require pressing it twice.
Your terminal already has some output from earlier commands. Practice: clear the screen (you learned two ways to do it), then use
echo to print a message and see clean output on a fresh start.Practice