To examine the value of a single variable, use C-h v
describe-variable), which reads a variable name using the
minibuffer, with completion. It displays both the value and the
documentation of the variable. For example,
C-h v fill-column RET
displays something like this:
fill-column's value is 75 Documentation: *Column beyond which automatic line-wrapping should happen. Automatically becomes buffer-local when set in any fashion.
The star at the beginning of the documentation indicates that this variable is a user option. C-h v is not restricted to user options; it allows any variable name.
The most convenient way to set a specific user option is with M-x set-variable. This reads the variable name with the minibuffer (with completion), and then reads a Lisp expression for the new value using the minibuffer a second time. For example,
M-x set-variable RET fill-column RET 75 RET
fill-column to 75.
M-x set-variable is limited to user option variables, but you can
set any variable with a Lisp expression, using the function
Here is a
setq expression to set
(setq fill-column 75)
To execute an expression like this one, go to the `*scratch*' buffer, type in the expression, and then type C-j. See section Lisp Interaction Buffers.
Setting variables, like all means of customizing Emacs except where otherwise stated, affects only the current Emacs session.
Go to the first, previous, next, last section, table of contents.