Xlib Reference Manual for Version 11 of the X Window System

H

Keysyms

This appendix provides a list of keysyms and a brief description of each keysym. Keysyms, as you may remember, are the portable representation of the symbols on the caps of keys.

The normal way to process a keyboard event is to use XLookupKeysym to determine the keysym or, if the application allows remapping of keys to strings, it may use XLookupString to get the ASCII string mapped to the key or keys pressed. This allows the application to treat keys in a simple and portable manner, and places the responsibility of tailoring the mapping between keys and keysyms on the server vendor.*

Many keysyms do not have obvious counterparts on the keyboard, but may be generated with certain key combinations. You will need a table for each particular model of hardware you intend the program to work on, to tell you what key combination results in each keysym that is not present on the caps of the keyboard. For real portability, you will want to use only the keysyms that are supported on all vendors equipment you intend the program to be displayed on.

The keysyms are defined in two standard include files: <X11/keysym.h> and <X11/keysymdef.h>. There are several families of keysyms defined in <X11/keysymdef.h>; LATIN1, LATIN2, LATIN3, LATIN4, KATAKANA, ARABIC, CYRILLIC, GREEK, TECHNICAL, SPECIAL, PUBLISHING, APL, HEBREW, and MISCELLANY. The <X11/keysym.h> file specifies which families are enabled. Only the LATIN1, LATIN2, LATIN3, LATIN4, GREEK, and MISCELLANY families are enabled in the standard <X11/keysym.h> file, probably because some compilers have an upper limit on the number of defined symbols that are allowed.

The developers of X at MIT say that to the best of their knowledge the Latin, Kana, Arabic, Cyrillic, Greek, Technical, APL, and Hebrew keysym sets are from the appropriate ISO (International Standards Organization) and/or ECMA international standards. There are no Technical, Special nor Publishing international standards, so these sets are based on Digital Equipment Corporation standards.

Keysyms are four byte long values. In the standard keysyms, the least significant 8 bits indicate a particular character within a set. and the next 8 bits indicate a particular keysym set. The order of the sets is important since not all the sets are complete. Each character set contains gaps where codes have been removed that were duplicates with codes in previous (that is, with lesser keysym set) character sets.

The 94 and 96 character code sets have been moved to occupy the right hand quadrant (decimal 129 - 256), so the ASCII subset has a unique encoding across the least significant byte which corresponds to the ASCII character code. However, this cannot be guaranteed in the keysym sets of future releases and does not apply to all of the MISCELLANY set.

As far as possible, keysym codes are the same as the character code. In the LATIN1 to LATIN4 sets, all duplicate glyphs occupy the same position. However, duplicates between GREEK and TECHNICAL do not occupy the same code position. Thus, applications wishing to use the TECHNICAL character set must transform the keysym using an array.

The MISCELLANY set is a miscellaneous collection of commonly occurring keys on keyboards. Within this set, the keypad symbols are generally duplicates of symbols found on keys on the alphanumeric part of the keyboard but are distinguished here because they often have distinguishable keycodes associated with them.

There is a difference between European and US usage of the names Pilcrow, Paragraph, and Section, as shown in Table H-1.

Table H-1. European vs. US usage of Pilcrow, Paragraph, and Section symbol names

X has adopted the names used by both the ISO and ECMA standards. Thus, XK_paragraph is what Europeans call the pilcrow sign, and XK_section is what they would call the paragraph sign. This favors the US usage.

Keysyms and Description

Tables H-2 through H-7 list the six commonly available sets of keysyms (MISCELLANY, LATIN1 through LATIN4, and GREEK) and describe each keysym briefly. When necessary and possible, these tables show a representative character or characters that might appear on the cap of the key or on the screen when the key or keys corresponding to the keysym were typed.

Table H-2. MISCELLANY

Keysym	Description
XK_Backspace	Backspace, Back Space, Back Char
XK_Tab	Tab
XK_Linefeed	Linefeed, LF
XK_Clear	Clear
XK_Return	Return, Enter
XK_Pause	Pause, Hold, Scroll Lock
XK_Escape	Escape
XK_Delete	Delete, Rubout
XK_Multi_key	Multi-key character preface
XK_Kanji	Kanji, Kanji convert
XK_Home	Home
XK_Left	Left, move left, left arrow
XK_Up	Up, move up, up arrow
XK_Right	Right, move right, right arrow
XK_Down	Down, move down, down arrow
XK_Prior	Prior, previous
XK_Next	Next
XK_End	End, EOL
XK_Begin	Begin, BOL
XK_Select	Select, mark
XK_Print	Print
XK_Execute	Execute, run, do
XK_Insert	Insert, insert here
XK_Undo	Undo, oops
XK_Redo	Redo, again
XK_Menu	Menu
XK_Find	Find, search
XK_Cancel	Cancel, stop, abort, exit
XK_Help	Help, question mark
XK_Break	Break
XK_Mode_switch	Mode switch, script switch, character set switch
XK_script_switch	Alias for mode switch, script switch, character set switch
XK_Num_Lock	Num Lock
XK_KP_Space	Keypad Space
XK_KP_Tab	Keypad Tab
XK_KP_Enter	Keypad Enter
XK_KP_F1	Keypad F1, PF1, a
XK_KP_F2	Keypad F2, PF2, b
XK_KP_F3	Keypad F3, PF3, c
XK_KP_F4	Keypad F4, PF4, d
XK_KP_Equal	Keypad equals sign
XK_KP_Multiply	Keypad multiplication sign, asterisk
XK_KP_Add	Keypad plus sign
XK_KP_Separator	Keypad separator, comma
XK_KP_Subtract	Keypad minus sign, hyphen
XK_KP_Decimal	Keypad decimal point, full stop
XK_KP_Divide	Keypad division sign, solidus
XK_KP_0	Keypad digit zero
XK_KP_1	Keypad digit one
XK_KP_2	Keypad digit two
XK_KP_3	Keypad digit three
XK_KP_4	Keypad digit four
XK_KP_5	Keypad digit five
XK_KP_6	Keypad digit six
XK_KP_7	Keypad digit seven
XK_KP_8	Keypad digit eight
XK_KP_9	Keypad digit nine
XK_F1	F1 function key
XK_F2	F2 function key
XK_F3	F3 function key
XK_F4	F4 function key
XK_F5	F5 function key
XK_F6	F6 function key
XK_F7	F7 function key
XK_F8	F8 function key
XK_F9	F9 function key
XK_F10	F10 function key
XK_F11	F11 function key
XK_L1	L1 function key
XK_F12	F12 function key
XK_L2	L2 function key
XK_F13	F13 function key
XK_L3	L3 function key
XK_F14	F14 function key
XK_L4	L4 function key
XK_F15	F15 function key
XK_L5	L5 function key
XK_F16	F16 function key
XK_L6	L6 function key
XK_F17	F17 function key
XK_L7	L7 function key
XK_F18	F18 function key
XK_L8	L8 function key
XK_F19	F19 function key
XK_L9	L9 function key
XK_F20	F20 function key
XK_L10	L10 function key
XK_F21	F21 function key
XK_R1	R1 function key
XK_F22	F22 function key
XK_R2	R2 function key
XK_F23	F23 function key
XK_R3	R3 function key
XK_F24	F24 function key
XK_R4	R4 function key
XK_F25	F25 function key
XK_R5	R5 function key
XK_F26	F26 function key
XK_R6	R6 function key
XK_F27	F27 function key
XK_R7	R7 function key
XK_F28	F28 function key
XK_R8	R8 function key
XK_F29	F29 function key
XK_R9	R9 function key
XK_F30	F30 function key
XK_R10	R10 function key
XK_F31	F31 function key
XK_R11	R11 function key
XK_F32	F32 function key
XK_R12	R12 function key
XK_R13	F33 function key
XK_F33	R13 function key
XK_F34	F34 function key
XK_R14	R14 function key
XK_F35	F35 function key
XK_R15	R15 function key
XK_Shift_L	Left Shift
XK_Shift_R	Right Shift
XK_Control_L	Left Control
XK_Control_R	Right Control
XK_Caps_Lock	Caps Lock
XK_Shift_Lock	Shift Lock
XK_Meta_L	Left Meta
XK_Meta_R	Right Meta
XK_Alt_L	Left Alt
XK_Alt_R	Right Alt
XK_Super_L	Left Super
XK_Super_R	Right Super
XK_Hyper_L	Left Hyper
XK_Hyper_R	Right Hyper

Table H-3. LATIN1

Table H-4. LATIN2

Table H-5. LATIN3

Table H-6. LATIN4

Table H-7. GREEK

* While keycode information is not necessary for normal application programming, it may be necessary for writing certain programs that change the keycode to keysym mapping. You will need to obtain a list of keycodes and their normal mappings from the system manufacturer. Any program that uses this mapping is not fully portable.