Emacs Manipulate Files

Emacs visits files in buffers. Editing changes the buffer first; saving writes its current contents to the associated pathname. Read minibuffer messages because permissions, conflicting disk changes, or other errors can prevent a write.

Visiting a File

Use C-x C-f, which runs find-file, then enter a pathname in the minibuffer and press Enter:

C-x C-f

Emacs opens an existing readable file in a buffer or prepares a new file-visiting buffer when the pathname is missing. In the second case, no disk file exists until a save succeeds.

You can use Tab completion while entering a pathname. Visiting a directory normally opens Dired, Emacs's directory editor, rather than treating the directory as a text file.

Saving the Current Buffer

Use C-x C-s, which runs save-buffer, to save the current file-visiting buffer:

C-x C-s

If the buffer has no associated filename, Emacs prompts for one. A successful write clears the buffer's modified indicator; a failure leaves the unsaved data in the buffer and reports an error.

Writing under Another Name

Use C-x C-w, which runs write-file, to prompt for a pathname, write the buffer there, and make the buffer visit that new file:

C-x C-w

This is the Emacs “Save As” behavior. It differs from merely writing a separate copy while continuing to visit the original pathname.

Reviewing Several Modified Buffers

Use C-x s, which runs save-some-buffers, to examine modified file-visiting buffers:

C-x s

Emacs normally asks whether to save each eligible modified buffer. Read the buffer name and answer deliberately; this is not an unconditional save-all shortcut.

Reverting from Disk

If a file changed on disk and you intentionally want to discard the buffer's current contents, run M-x revert-buffer and review the confirmation prompt. Reverting can destroy unsaved buffer edits, so use it only after confirming which source should win.

To compare before deciding, save a separate copy or use version-control and diff tools. Avoid treating reload operations as harmless when the buffer is modified.

Summary

You can now manage file-backed buffers without confusing visits and writes.

1. Visit a pathname with C-x C-f.
2. Create a missing file only when its buffer is saved.
3. Save the current buffer with C-x C-s.
4. Save under a new visited name with C-x C-w.
5. Review several modified buffers with C-x s.