Sometimes the minibuffer starts out with text in it. For example, when you are supposed to give a file name, the minibuffer starts out containing the default directory, which ends with a slash. This is to inform you which directory the file will be found in if you do not specify a directory.
For example, the minibuffer might start out with these contents:
Find File: /u2/emacs/src/
where ‘Find File: ’ is the prompt. Typing buffer.c specifies the file /u2/emacs/src/buffer.c. To find files in nearby directories, use ..; thus, if you type ../lisp/simple.el, you will get the file named /u2/emacs/lisp/simple.el. Alternatively, you can kill with M-DEL the directory names you don’t want (see Words).
If you don’t want any of the default, you can kill it with C-a C-k. But you don’t need to kill the default; you can simply ignore it. Insert an absolute file name, one starting with a slash or a tilde, after the default directory. For example, to specify the file /etc/termcap, just insert that name, giving these minibuffer contents:
Find File: /u2/emacs/src//etc/termcap
SXEmacs gives a special meaning to a double slash (which is not normally a useful thing to write): it means, “ignore everything before the second slash in the pair.” Thus, ‘/u2/emacs/src/’ is ignored in the example above, and you get the file /etc/termcap.
If you set
nil, the default
directory is not inserted in the minibuffer. This way, the minibuffer
starts out empty. But the name you type, if relative, is still
interpreted with respect to the same default directory.