在Emacs中创建一个文件时，无法打开目录

Question

I use Cx Cf and C -X Cs to save a file to directory "test", then I can not open the test directory with "tab", it says "Dired (directory): ~/test.....".

I want to know what is the wrong and the correct method to create a file in emacs, thanks!

Answer 1

Emacs distinguishes between files and buffers . You do all your editing in buffers, which do not necessarily have to be associated with a file (see, eg, the *scratch* buffer). However, you often want to edit a buffer that is associated with a file. In that case you visit (Emacs lingo for "open") said file with Cx Cf .

Let's say you have a directory "test" in your home directory, and in that directory a single file "foo.txt". If you want to edit the contents of that file, visit it by typing:

Cx Cf ~/test/foo.txt RET

That's easy enough: now you get a new buffer in Emacs which is conveniently named after the file you're visiting ("foo.txt"). If you want to store changes you've made in the buffer back to the associated file, you type Cx Cs , and Emacs will write the contents of the buffer to the file "~/test/foo.txt".

This mechanism also works for files that do not exist when you start editing!

If you type, say,

Cx Cf ~/test/bar.txt RET

You get a buffer associated with a (yet non-existent) file "bar.txt" in the directory "~/test". Again, you can edit that buffer to your liking and then save the buffer with Cx Cs . The first time you do that, a new file is created.

If you want to create a buffer named "baz" that is not associated with any file, type

Cx b baz RET

Since it is not associated with a file yet, typing Cx Cs in that buffer will prompt you to specify a file-name. After saving, the buffer will be associated with the file you specified.

Finally, if you're in a buffer that is associated with a file, but you want to save it to a different file, you can do so with Cx Cw , which will give you the same prompt as in the previous case. Again, the buffer will be associated after saving with the file you provide.

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Tab completion does work in all of the commands that ask you for a file name. If you think it doesn't then it might be because the file you think should be completed does not exist (also beware of upper-/lower-case distinctions in file names), or because another file with the same prefix forbids further disambiguation. Tapping TAB twice should list the available completions in a temporary buffer, letting you continue specifying the path name until it is complete.

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Dired mode is pretty much orthogonal to all of the above. It is a mode for "editing" directories, ie, doing file system operations. You invoke it by typing Cx d , which you may have typed accidentally?! It is quite powerful, but also quite complex. See here for its documentation.