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A defined abbrev is a word which expands, if you insert it, into some different text. Abbrevs are defined by the user to expand in specific ways. For example, you might define `foo' as an abbrev expanding to `find outer otter'. Then you would be able to insert `find outer otter ' into the buffer by typing f o o SPC.


Abbrev Concepts

An abbrev is a word which has been defined to expand into a specified expansion. When you insert a word-separator character following the abbrev, that expands the abbrev--replacing the abbrev with its expansion. For example, if `foo' is defined as an abbrev expanding to `find outer otter', then you can insert `find outer otter.' into the buffer by typing f o o ..


Abbrev definitions can be mode-specific---active only in one major mode. Abbrevs can also have global definitions that are active in all major modes. The same abbrev can have a global definition and various mode-specific definitions for different major modes. A mode specific definition for the current major mode overrides a global definition.

Abbrevs can be defined interactively during the editing session. Lists of abbrev definitions can also be saved in files and reloaded in later sessions. Some users keep extensive lists of abbrevs that they load in every session.

Defining Abbrevs

C-x a g
Define an abbrev, using one or more words before point as its expansion (add-global-abbrev).
C-x a l
Similar, but define an abbrev specific to the current major mode (add-mode-abbrev).
C-x a i g
Define a word in the buffer as an abbrev (inverse-add-global-abbrev).
C-x a i l
Define a word in the buffer as a mode-specific abbrev (inverse-add-mode-abbrev).
M-x kill-all-abbrevs
This command discards all abbrev definitions currently in effect, leaving a blank slate.

The usual way to define an abbrev is to enter the text you want the abbrev to expand to, position point after it, and type C-x a g (add-global-abbrev). This reads the abbrev itself using the minibuffer, and then defines it as an abbrev for one or more words before point. Use a numeric argument to say how many words before point should be taken as the expansion. For example, to define the abbrev `foo' as mentioned above, insert the text `find outer otter' and then type C-u 3 C-x a g f o o RET.

An argument of zero to C-x a g means to use the contents of the region as the expansion of the abbrev being defined.

The command C-x a l (add-mode-abbrev) is similar, but defines a mode-specific abbrev. Mode specific abbrevs are active only in a particular major mode. C-x a l defines an abbrev for the major mode in effect at the time C-x a l is typed. The arguments work the same as for C-x a g.

If the text already in the buffer is the abbrev, rather than its expansion, use command C-x a i g (inverse-add-global-abbrev) instead of C-x a g, or use C-x a i l (inverse-add-mode-abbrev) instead of C-x a l. These commands are called "inverse" because they invert the meaning of the two text strings they use (one from the buffer and one read with the minibuffer).

To change the definition of an abbrev, just define a new definition. When the abbrev has a prior definition, the abbrev definition commands ask for confirmation for replacing it.

To remove an abbrev definition, give a negative argument to the abbrev definition command: C-u - C-x a g or C-u - C-x a l. The former removes a global definition, while the latter removes a mode-specific definition.

M-x kill-all-abbrevs removes all the abbrev definitions there are, both global and local.

Controlling Abbrev Expansion

An abbrev expands whenever it is present in the buffer just before point and you type a self-inserting whitespace or punctuation character (SPC, comma, etc.). More precisely, any character that is not a word constituent expands an abbrev, and any word constituent character can be part of an abbrev. The most common way to use an abbrev is to insert it and then insert a punctuation character to expand it.

Abbrev expansion preserves case; thus, `foo' expands into `find outer otter'; `Foo' into `Find outer otter', and `FOO' into `FIND OUTER OTTER' or `Find Outer Otter' according to the variable abbrev-all-caps (a non-nil value chooses the first of the two expansions).

These commands are used to control abbrev expansion:

C-x a e
M-x expand-region-abbrevs
Expand some or all abbrevs found in the region.

You may wish to expand an abbrev with a prefix attached; for example, if `cnst' expands into `construction', you might want to use it to enter `reconstruction'. It does not work to type recnst, because that is not necessarily a defined abbrev. What you can do is use the command M-' (abbrev-prefix-mark) in between the prefix `re' and the abbrev `cnst'. First, insert `re'. Then type M-'; this inserts a hyphen in the buffer to indicate that it has done its work. Then insert the abbrev `cnst'; the buffer now contains `re-cnst'. Now insert a non-word character to expand the abbrev `cnst' into `construction'. This expansion step also deletes the hyphen that indicated M-' had been used. The result is the desired `reconstruction'.

If you actually want the text of the abbrev in the buffer, rather than its expansion, you can accomplish this by inserting the following punctuation with C-q. Thus, foo C-q , leaves `foo,' in the buffer.

If you expand an abbrev by mistake, you can undo the expansion and bring back the abbrev itself by typing C-_ (undo). This also undoes the insertion of the non-word character that expanded the abbrev. If the result you want is the terminating non-word character plus the unexpanded abbrev, you must reinsert the terminating character, quoting it with C-q.


Expanding an abbrev runs the hook pre-abbrev-expand-hook (see section Hooks).

Examining and Editing Abbrevs

M-x list-abbrevs
Display a list of all abbrev definitions.
M-x edit-abbrevs


"dk"	       0    "define-key"
"dfn"	       0    "definition"




M-x edit-abbrevs allows you to add, change or kill abbrev definitions by editing a list of them in an Emacs buffer. The list has the same format described above. The buffer of abbrevs is called `*Abbrevs*', and is in Edit-Abbrevs mode. Type C-c C-c in this buffer to install the abbrev definitions as specified in the buffer--and delete any abbrev definitions not listed.

The command edit-abbrevs is actually the same as list-abbrevs except that it selects the buffer `*Abbrevs*' whereas list-abbrevs merely displays it in another window.

Saving Abbrevs

These commands allow you to keep abbrev definitions between editing sessions.

M-x write-abbrev-file RET file RET
Write a file file describing all defined abbrevs.
M-x read-abbrev-file RET file RET
Read the file file and define abbrevs as specified therein.
M-x quietly-read-abbrev-file RET file RET
M-x define-abbrevs
Define abbrevs from definitions in current buffer.
M-x insert-abbrevs
Insert all abbrevs and their expansions into current buffer.


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. M-x quietly-read-abbrev-file is the same except that it does not display a message in the echo area saying that it is doing its work; it is actually useful primarily in the `.emacs' file. If an empty argument is given to either of these functions, they use the file name specified in the variable abbrev-file-name, which is by default "~/.abbrev_defs".

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). This feature can be inhibited by setting the variable save-abbrevs to nil.

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 before point, describing all current abbrev definitions; M-x define-abbrevs parses the entire current buffer and defines abbrevs accordingly.

Dynamic Abbrev Expansion

The abbrev facility described above operates automatically as you insert text, but all abbrevs must be defined explicitly. By contrast, dynamic abbrevs allow the meanings of abbrevs to be determined automatically from the contents of the buffer, but dynamic abbrev expansion happens only when you request it explicitly.


For example, if the buffer contains `does this follow ' and you type f o M-/, the effect is to insert `follow' because that is the last word in the buffer that starts with `fo'. A numeric argument to M-/ says to take the second, third, etc. distinct expansion found looking backward from point. Repeating M-/ searches for an alternative expansion by looking farther back. After the entire buffer before point has been considered, the buffer after point is searched.

A negative argument to M-/, as in C-u - M-/, says to search first for expansions after point, and only later search the text before point. If you repeat the M-/ to look for another expansion, do not specify an argument. This tries all the expansions after point and then the expansions before point.


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