Files, buffers, and windows

Each buffer has a name. By default, buffers that are associated with particular files have the name of that file (not including the name of the directory containing it), possibly followed by a number in angle brackets to distinguish multiple files (from different directories) with the same name.

C-x C-f

prompts for a file name and sets the current window to displaying that file in a buffer by the same name. If a buffer displaying that file already exists, this command merely switches the window to that buffer. If the file does not exist, the buffer is initially empty. The buffer is subsequently associated with the file. This process is called finding the file.

C-x 4 C-f

prompts for a file name, goes to the next window on the screen (creating a new one, if there is only one), and then acts like C-x C-f.

C-x C-s

saves the current buffer in its associated file, if the buffer has been modified. If the file being saved exists, then the old version is first renamed to have a tilde (~ ) appended to its name, if no such file yet exists.

C-x C-w

prompts for a file name and saves the current buffer into that file. Generally, it is preferable and safer to use C-x C-f or C-x 4 C-f and then use C-x C-s, but sometimes this command is handy.

C-x i

prompts for a file name and inserts that file at the point. It does not associate the inserted file with the current buffer.

M-x revert-buffer

throws away the contents of the current buffer and restores the contents of the associated file. It will ask you to confirm these actions before taking them.

C-x o

makes another window on the screen (if any) the current window.

C-x 0

deletes the current window, expanding another window to take its place. The buffer being displayed in the current window is not affected.

C-x 1

makes the current window the only window on the screen, deleting all others. The buffers being displayed in the deleted windows are not affected.

C-x 2

splits the current window into two vertically (one on top of the other), both displaying the same buffer.

C-x 3

splits the current window into two horizontally (beside each other), each displaying the same buffer.

C-x b

prompts for a buffer name and switches the current window to that buffer. When trying to move to a buffer associated with a file, it is better to use the file finding commands.

C-x C-b

lists the active buffers in a window.

C-x k

prompts for a buffer name and deletes that buffer, displaying some other buffer in the current window. You will be warned if the contents of the buffer have been modified and not yet saved.