Thursday, September 4, 2008

Managing Bash with Key Sequences in Ubuntu

Sometimes, you’ll enter a command from the Bash command line and either nothing happens at all or else something totally unexpected happens. In such an event, it’s good to know that some key sequences are available to perform basic Bash management tasks. Here are some of the most useful key sequences.

Ctrl+C: Use this key sequence to quit a command that is not responding (or simply takes too long to complete). This key sequence works in most scenarios where the command is operational and producing output to the screen. In general, Ctrl+C is also a good choice if you absolutely don’t have a clue as to what’s happening and you just want to terminate the command that’s running in your shell. If used in the shell itself, it will close the shell as well.

Ctrl+D: This key sequence is used to send the “end of file” (EOF) signal to a command.
Use this when the command is waiting for more input, which is indicated by the secondary prompt (>). You can also use this key sequence to close a shell session.

Ctrl+R: This is the reversed search feature. It will open the “reversed I-search” prompt, which helps you locate commands that you used previously. The Ctrl+R key sequence searches the Bash history, and the feature is especially useful when working with longer commands. As before, type the first characters of the command and you will see the last command you’ve used that started with the same characters.

Ctrl+Z: Some people use Ctrl+Z to stop a command that is running interactively on the console (in the foreground). Although it does stop the command, it does not terminate it. A command that is stopped with Ctrl+Z is merely paused, so that you can easily start it in the background using the bg command or in the foreground again with the fg command. To start the command again, you need to refer to the job number that the program is using. You can see a list of these job numbers using the jobs command.

Source of Information : Apress Beginning Ubuntu Server Administration

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