The Compose key ( English compose , composed) is a special dead key on a computer keyboard , the following key presses are grouped by their pressing to a not in a keyboard layout to produce existing character. It is mainly found on Unix operating systems.
The result character usually results from a relatively intuitive superimposition of the original symbols or letters.
A keyboard symbol for the Compose key is standardized in ISO / IEC 9995 -7 as symbol 15 “Compose Character” , and in DIN ISO 7000 “Graphic symbols on devices” as symbol ISO-7000-2021. This character is contained in Unicode from version 3.0 in the block Various technical characters as U + 2384 composition symbol (⎄).
|Button 1||Button 2||Result|
|"||a||Ä||Umlaut / Trema|
|^||a||â||Letter with circumflex|
|,||c||ç||Accented Letter ( Cedilla )|
|<||<||«||Quotation marks (guillemets)|
|>||>||»||Quotation marks (guillemets)|
|>||'||'||typographically correct apostrophe|
|=||e||€||the euro sign|
The key combinations can vary depending on the implementation and language setting. Under X.Org , the abbreviations can be looked up and modified in a subdirectory specified in the file /usr/share/X11/locale/locale.dir for the corresponding locale . The file, which contains all possible compose sequences, can often be found under /usr/share/X11/locale/en_US.UTF-8/Compose . In most distributions, contrary to the obvious assumption, this file is used for all UTF-8 locales, such as de_DE.UTF-8 .
Only a few keyboards, mostly for computers from certain manufacturers (such as Sun Microsystems ), have a separate Compose key. Under many Linux distributions , it is simulated using a combination of the Shift key and Alt Gr ; the right Windows key is also often used for this. If you use your own xmodmap , the Compose key can be triggered with the help of the “Multi_key” value .
For users of other operating systems, there is sometimes the option of emulating the Compose key using software . For Windows, for example, there is an open source program called AllChars that allows this within the framework of the active character set table and the selected character set ; the portable Windows driver of the Neo keyboard layout enables the input of all unixoid composite sequences.
- Partial list of Compose sequences in Linux (English)
- Create key sequences for the ISO Latin-1 character set in the Sun Solaris User Guide, 1998 edition, from p. 493 (PDF; 2.3 MB)
- Project overview for AllChars at SourceForge - a Compose key emulator for Windows