8.1 Minibuffers for File Names

Commands such as C-x C-f (find-file) use the minibuffer to read a file name argument (see Basic Files). When the minibuffer is used to read a file name, it typically starts out with some initial text ending in a slash. This is the default directory. For example, it may start out like this:

     Find File: /u2/emacs/src/

Here, ‘Find File: ’ is the prompt and ‘/u2/emacs/src/’ is the default directory. If you now type buffer.c as input, that specifies the file /u2/emacs/src/buffer.c. See File Names, for information about the default directory.

You can specify the parent directory by adding ..: for example, /u2/emacs/src/../lisp/simple.el is equivalent to /u2/emacs/lisp/simple.el. Alternatively, you can use M-<DEL> to kill directory names backwards (see Words).

To specify a file in a completely different directory, you can kill the entire default with C-a C-k (see Minibuffer Edit). Alternatively, you can ignore the default, and enter an absolute file name starting with a slash or a tilde after the default directory. For example, you can specify /etc/termcap as follows:

     Find File: /u2/emacs/src//etc/termcap

Emacs interprets a double slash as “ignore everything before the second slash in the pair.” In the example above, /u2/emacs/src/ is ignored, so the argument you supplied is /etc/termcap. The ignored part of the file name is dimmed if the terminal allows it (to disable this dimming, turn off File Name Shadow mode with the command M-x file-name-shadow-mode.)

Emacs interprets ~/ as your home directory. Thus, ~/foo/bar.txt specifies a file named bar.txt, inside a directory named foo, which is in turn located in your home directory. In addition, ~user-id/ means the home directory of a user whose login name is user-id. Any leading directory name in front of the ~ is ignored: thus, /u2/emacs/~/foo/bar.txt is equivalent to ~/foo/bar.txt.

On MS-Windows and MS-DOS systems, where a user doesn't always have a home directory, Emacs uses several alternatives. For MS-Windows, see Windows HOME; for MS-DOS, see HOME on MS-DOS. On these systems, the ~user-id/ construct is supported only for the current user, i.e., only if user-id is the current user's login name.

To prevent Emacs from inserting the default directory when reading file names, change the variable insert-default-directory to nil. In that case, the minibuffer starts out empty. Nonetheless, relative file name arguments are still interpreted based on the same default directory.