That's a practical question!
If you press the <Tab> key for tab completion and there's no match (meaning no file, directory, or command starts with what you've typed so far), then nothing happens.
- Your cursor will just stay where it is.
- Your partial command or path won't change.
- You won't hear any sound or see any error message.
Essentially, if the shell can't find anything that uniquely or non-uniquely matches your input, it just assumes you want to continue typing yourself. It's a silent failure in terms of completion, which is often preferable to an annoying error sound or message.
Example:
Let's say you are in /home/labex/project and type:
cd mynonexistentfolder<Tab>If there is no folder named mynonexistentfolder (or anything starting with mynonexistentfolder), then pressing <Tab> will do nothing. Your input will remain cd mynonexistentfolder, and you'll have to either delete it or press Enter to get an "No such file or directory" error.
This behavior helps you know immediately that what you've typed doesn't exist or isn't accessible from your current location, prompting you to check your spelling or the current directory's contents (e.g., using ls).
Does that make sense?
