Variable: fill-column

fill-column is a customizable and buffer-local variable defined in buffer.c.

Documentation

Column beyond which automatic line-wrapping should happen.

It is used by filling commands, such as fill-region and fill-paragraph, and by auto-fill-mode, which see. See also current-fill-column. Interactively, you can set the buffer local value using C-x f (set-fill-column).

View in manual

Probably introduced at or before Emacs version 18.

Source Code

// Defined in /usr/src/emacs/src/buffer.c
  DEFVAR_PER_BUFFER ("fill-column", &BVAR (current_buffer, fill_column),
		     Qintegerp,
		     doc: /* Column beyond which automatic line-wrapping should happen.
It is used by filling commands, such as `fill-region' and `fill-paragraph',
and by `auto-fill-mode', which see.
See also `current-fill-column'.
Interactively, you can set the buffer local value using \\[set-fill-column].  */);