Which feature allows a user to quickly complete commands or file names once they have typed enough at the prompt to make it unique?

The feature that enables users to quickly complete commands or file names after typing enough characters to make the input unique is known as tab-completion. This functionality is a convenience feature available in various command-line interfaces, including the shell environments in RHEL Linux, such as Bash.

When a user starts typing a command or a filename and then presses the Tab key, the shell checks to see if the input uniquely identifies a command or file within the current context. If it does, the shell will automatically fill in the rest of the command or filename, saving the user time and reducing the chances of typographical errors. If the input is not unique, the shell may either complete what it can or display a list of possible completions, prompting the user to narrow down their input.

This feature significantly enhances user productivity and efficiency in navigating the filesystem and executing commands by minimizing the need for memorization and repeated typing. Its implementation in the Bash shell, which is commonly used in RHEL Linux environments, showcases the emphasis on user-friendly interaction with the command line.