The Mode Line
Each text window's last line is a mode line, which describes what is going on in that window. When there is only one text window, the mode line appears right above the echo area; it is the next-to-last line in the frame. The mode line starts and ends with dashes. On a text-mode display, the mode line is in inverse video if the terminal supports that; on a graphics display, the mode line has a 3D box appearance to help it stand out.
Normally, the mode line looks like this:
-cs:ch buf (major minor)--line--pos------
This gives information about the buffer being displayed in the window: the buffer's name, what major and minor modes are in use, whether the buffer's text has been changed, and how far down the buffer you are currently looking.
ch contains two stars ** if the text in the buffer has been edited (the buffer is "modified"), or -- if the buffer has not been edited. For a read-only buffer, it is %* if the buffer is modified, and %% otherwise.
buf is the name of the window's buffer. In most cases this is the same as the name of a file you are editing. See Buffers.
The buffer displayed in the selected window (the window that the cursor is in) is also Emacs's current buffer, the one that editing takes place in. When we speak of what some command does to "the buffer," we are talking about the current buffer.
line is L followed by the current line number of point. This is present when Line Number mode is enabled (which it normally is). You can optionally display the current column number too, by turning on Column Number mode (which is not enabled by default because it is somewhat slower). See Optional Mode Line.
pos tells you whether there is additional text above the top of the window, or below the bottom. If your buffer is small and it is all visible in the window, pos is All. Otherwise, it is Top if you are looking at the beginning of the buffer, Bot if you are looking at the end of the buffer, or nn%, where nn is the percentage of the buffer above the top of the window.
major is the name of the major mode in effect in the buffer. At any time, each buffer is in one and only one of the possible major modes. The major modes available include Fundamental mode (the least specialized), Text mode, Lisp mode, C mode, Texinfo mode, and many others. See Major Modes, for details of how the modes differ and how to select one.
Some major modes display additional information after the major mode name. For example, Rmail buffers display the current message number and the total number of messages. Compilation buffers and Shell buffers display the status of the subprocess.
minor is a list of some of the minor modes that are turned on at the moment in the window's chosen buffer. For example, Fill means that Auto Fill mode is on. Abbrev means that Word Abbrev mode is on. Ovwrt means that Overwrite mode is on. See
