These commands allow you to keep abbrev definitions between editing sessions.
M-x write-abbrev-file reads a file name using the minibuffer and then writes a description of all current abbrev definitions into that file. This is used to save abbrev definitions for use in a later session. The text stored in the file is a series of Lisp expressions that, when executed, define the same abbrevs that you currently have.
M-x read-abbrev-file reads a file name using the minibuffer
and then reads the file, defining abbrevs according to the contents of
the file. The function
quietly-read-abbrev-file is similar
except that it does not display a message in the echo area; you cannot
invoke it interactively, and it is used primarily in your init file
(see Init File). If either of these functions is called with
nil as the argument, it uses the file given by the variable
abbrev-file-name, which is ~/.emacs.d/abbrev_defs by
default. This is your standard abbrev definition file, and Emacs
loads abbrevs from it automatically when it starts up. (As an
exception, Emacs does not load the abbrev file when it is started in
batch mode. See Initial Options, for a description of batch mode.)
Emacs will offer to save abbrevs automatically if you have changed
any of them, whenever it offers to save all files (for C-x s or
C-x C-c). It saves them in the file specified by
abbrev-file-name. This feature can be inhibited by setting the
nil; setting it to
silently will save the abbrevs automatically without asking.
The commands M-x insert-abbrevs and M-x define-abbrevs are similar to the previous commands but work on text in an Emacs buffer. M-x insert-abbrevs inserts text into the current buffer after point, describing all current abbrev definitions; M-x define-abbrevs parses the entire current buffer and defines abbrevs accordingly.