32.6 Command Completion

Emacs has a great feature called command completion . Basically, command completion means that Emacs will let you type the absolute minimum and it will fill in the rest. You can use Emacs whenever you're typing a filename, a buffer name, a command name, or a variable name. Simply type enough of the name to be "unique" (usually the first few letters), followed by a TAB. Emacs will fill in the rest of the name for you. If the name isn't unique - that is, if there are other filenames that start with the same letters-Emacs will show you the alternatives. Type a few more letters to select the file you want, then press TAB again.

For example, if I'm trying to load the file outline.txt , I can simply give the command CTRL-x   CTRL-f   out   TAB . Providing that there are no other filenames beginning with the letters out , Emacs will fill in the rest of the filename. When I see that it's correct, I press RETURN, and I'm done.

When you use command completion, always make sure that Emacs has successfully found the file you want. If you don't, the results may be strange: you may end up with a partial filename or with the wrong file.