1 This directory contains files of elisp that customize Emacs for certain
4 When Emacs opens a new terminal, it checks the TERM environment variable to
5 see what type of terminal the user is running on, searches for an elisp file
6 named "term/${TERM}.el", and if one exists, loads it. If Emacs finds no
7 suitable file, then it strips the last hyphen and what follows it from TERM,
8 and tries again. If that still doesn't yield a file, then the previous hyphen
9 is stripped, and so on until all hyphens are gone. For example, if the
10 terminal type is `aaa-48-foo', Emacs will try first `term/aaa-48-foo.el', then
11 `term/aaa-48.el' and finally `term/aaa.el'. Emacs stops searching at the
12 first file found, and will not load more than one file for any terminal. Note
13 that it is not an error if Emacs is unable to find a terminal initialization
14 file; in that case, it will simply proceed with the next step without loading
17 Once the file has been loaded (or the search failed), Emacs tries to call a
18 function named `terminal-init-TERMINALNAME' (eg `terminal-init-aaa-48' for the
19 `aaa-48' terminal) in order to initialize the terminal. Once again, if the
20 function is not found, Emacs strips the last component of the name and tries
21 again using the shorter name. This search is independent of the previous file
22 search, so that you can have terminal initialization functions for a family of
23 terminals collected in a single file named after the family name, and users
24 may put terminal initialization functions directly in their .emacs files.
26 Note that an individual terminal file is loaded only once in an Emacs
27 session; if the same terminal type is opened again, Emacs will simply call the
28 initialization function without reloading the file. Therefore, all the actual
29 initialization actions should be collected in terminal-init-* functions; the
30 file should not contain any top-level form that is not a function or variable
31 declaration. Simply loading the file should not have any side effect.
33 Similarly, the terminal initialization function is called only once on any
34 given terminal, when the first frame is created on it. The function is not
35 called for subsequent frames on the same terminal. Therefore, terminal-init-*
36 functions should only modify terminal-local variables (such as
37 `local-function-key-map') and terminal parameters. For example, it is not
38 correct to modify frame parameters, since the modifications will only be
39 applied for the first frame opened on the terminal.
42 When writing terminal packages, there are some things it is good to keep in
45 First, about keycap names. Your terminal package can create any keycap
46 cookies it likes, but there are good reasons to stick to the set recognized by
47 the X-windows code whenever possible. The key symbols recognized by Emacs
48 are listed in src/term.c; look for the string `keys' in that file.
50 For one thing, it means that you'll have the same Emacs key bindings on in
51 terminal mode as on an X console. If there are differences, you can bet
52 they'll frustrate you after you've forgotten about them.
54 For another, the X keysms provide a standard set of names that Emacs knows
55 about. It tries to bind many of them to useful things at startup, before your
56 .emacs is read (so you can override them). In some ways, the X keysym standard
57 is a admittedly poor one; it's incomplete, and not well matched to the set of
58 `virtual keys' that UNIX terminfo(3) provides. But, trust us, the alternatives
61 This doesn't mean that if your terminal has a "Cokebottle" key you shouldn't
62 define a [cokebottle] keycap. But if you must define cookies that aren't in
63 that set, try to pattern them on the standard terminfo variable names for
64 clarity; also, for a fighting chance that your binding may be useful to someone
67 For example, if your terminal has a `find' key, observe that terminfo
68 supports a key_find capability and call your cookie [find].
70 Here is a complete list, with corresponding X keysyms.
72 -----------------------------------------------------------------------------
73 Variable name cap X Keysym Description
74 -------------- --- ------------ -------------------------------------
75 key_down kd down Sent by terminal down arrow key
76 key_up ku up Sent by terminal up arrow key
77 key_left kl left Sent by terminal left arrow key
78 key_right kr right Sent by terminal right arrow key
79 key_home kh home Sent by home key.
80 key_backspace kb Sent by backspace key
81 key_dl kd deleteline Sent by delete line key.
82 key_il kA insertline Sent by insert line.
83 key_dc kD Sent by delete character key.
84 key_ic kI insertchar (1) Sent by ins char/enter ins mode key.
85 key_eic KM Sent by rmir or smir in insert mode.
86 key_clear kC Sent by clear screen or erase key.
87 key_eos kS Sent by clear-to-end-of-screen key.
88 key_eol kE Sent by clear-to-end-of-line key.
89 key_sf kF Sent by scroll-forward/down key
90 key_sr kR Sent by scroll-backward/up key
91 key_npage kN next (2) Sent by next-page key
92 key_ppage kP prior (2) Sent by previous-page key
93 key_stab kT Sent by set-tab key
94 key_ctab kt Sent by clear-tab key
95 key_catab ka Sent by clear-all-tabs key.
96 key_enter @8 kp-enter Enter/send (unreliable)
97 key_print %9 print print or copy
98 key_ll kH Sent by home-down key
99 key_a1 K1 kp-1 Upper left of keypad
100 key_a3 K3 kp-3 Upper right of keypad
101 key_b2 K2 kp-5 Center of keypad
102 key_c1 K4 kp-7 Lower left of keypad
103 key_c3 K5 kp-9 Lower right of keypad
104 key_btab kB backtab Back tab key
105 key_beg @1 begin beg(inning) key
106 key_cancel @2 cancel cancel key
107 key_close @3 close key
108 key_command @4 execute (3) cmd (command) key
110 key_create @6 create key
111 key_end @7 end end key
116 key_message %3 message key
118 key_next %5 next (2) next object key
120 key_options %7 menu (3) options key
121 key_previous %8 previous (2) previous object key
122 key_redo %0 redo redo key
123 key_reference &1 ref(erence) key
124 key_refresh &2 refresh key
125 key_replace &3 replace key
126 key_restart &4 reset (3) restart key
127 key_resume &5 resume key
129 key_sbeg &9 shifted beginning key
130 key_select *6 select select key
131 key_suspend &7 suspend key
132 key_undo &8 undo undo key
134 key_scancel &0 shifted cancel key
135 key_scommand *1 shifted command key
136 key_scopy *2 shifted copy key
137 key_screate *3 shifted create key
138 key_sdc *4 shifted delete char key
139 key_sdl *5 shifted delete line key
140 key_send *7 shifted end key
141 key_seol *8 shifted clear line key
142 key_sexit *9 shifted exit key
143 key_sf kF shifted find key
144 key_shelp #1 shifted help key
145 key_shome #2 shifted home key
146 key_sic #3 shifted input key
147 key_sleft #4 shifted left arrow key
148 key_smessage %a shifted message key
149 key_smove %b shifted move key
150 key_snext %c shifted next key
151 key_soptions %d shifted options key
152 key_sprevious %e shifted prev key
153 key_sprint %f shifted print key
154 key_sredo %g shifted redo key
155 key_sreplace %h shifted replace key
156 key_sright %i shifted right arrow
157 key_sresume %j shifted resume key
158 key_ssave !1 shifted save key
159 key_suspend !2 shifted suspend key
160 key_sundo !3 shifted undo key
162 key_f0 k0 f0 (4) function key 0
163 key_f1 k1 f1 function key 1
164 key_f2 k2 f2 function key 2
165 key_f3 k3 f3 function key 3
166 key_f4 k4 f4 function key 4
167 key_f5 k5 f5 function key 5
168 key_f6 k6 f6 function key 6
169 key_f7 k7 f7 function key 7
170 key_f8 k8 f8 function key 8
171 key_f9 k9 f9 function key 9
172 key_f10 k; f10 (4) function key 10
173 key_f11 F1 f11 function key 11
175 key_f35 FP f35 function key 35
176 key_f36 FQ function key 36
178 key_f64 k1 function key 64
180 (1) The terminfo documentation says this may be the 'insert character' or
181 `enter insert mode' key. Accordingly, key_ic is mapped to the `insertchar'
182 keysym if there is also a key_dc key; otherwise it's mapped to `insert'.
183 The presumption is that keyboards with `insert character' keys usually
184 have `delete character' keys paired with them.
186 (2) If there is no key_next key but there is a key_npage key, key_npage
187 will be bound to the `next' keysym. If there is no key_previous key but
188 there is a key_ppage key, key_ppage will be bound to the `previous' keysym.
190 (3) Sorry, these are not exact but they're the best we can do.
192 (4) The uses of the "k0" capability are inconsistent; sometimes it
193 describes F10, whereas othertimes it describes F0 and "k;" describes F10.
194 Emacs attempts to politely accommodate both systems by testing for
195 "k;", and if it is present, assuming that "k0" denotes F0, otherwise F10.
196 -----------------------------------------------------------------------------
198 The following X keysyms do *not* have terminfo equivalents. These are
199 the cookies your terminal package will have to set up itself, if you want them:
224 In general, you should not bind any of the standard keysym names to
225 functions in a terminal package. There's code in loaddefs.el that does that;
226 the less people make exceptions to that, the more consistent an interface Emacs
227 will have across different keyboards. Those exceptions should go in your
230 Finally, if you're using a USL UNIX or a Sun box or anything else with the
231 USL version of curses(3) on it, bear in mind that the original curses(3) had
232 (and still has) a very much smaller set of keycaps. In fact, the reliable
233 ones were just the arrow keys and the first ten function keys. If you care
234 about making your package portable to older Berkeley machines, don't count on
235 the setup code to bind anything else.
237 If your terminal's arrow key sequences are so funky that they conflict with
238 normal Emacs key bindings, the package should set up a function called
239 (enable-foo-arrow-keys), where `foo' becomes the terminal name, and leave
240 it up to the user's .emacs file whether to call it.
242 Before writing a terminal-support package, it's a good idea to read the
243 existing ones and learn the common conventions.
HCoop / bpt / emacs.git / blob