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make edlin understand a few important control keys

Dear all,

the patch attached to this e-mail teaches edlin.erl a few more important
control keys that many users might have become *VERY* accustomed to. The
control keys are:

 - <CTRL>+W	: backward kill word
 - <CTRL>+U	: backward kill line
 - <HOME>	: goto start of line
 - <END>	: goto end of line
 - <CTRL>+<LEFT>  : backward word
 - <CTRL>+<RIGHT> : forward word

With this patch in place, command line editing in erlang's own shell as
well as in any input using io:get_line() comes a little closer to that
in many contemporary shells.

Kind regards,

--
Dr. Stefan Zegenhagen

arcutronix GmbH
Garbsener Landstr. 10
30419 Hannover
Germany

Tel:   +49 511 277-2734
Fax:   +49 511 277-2709
Email: stefan.zegenhagen@arcutronix.com
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>From 39f497adec90fc397f366da275fd5a7ca748cc5f Mon Sep 17 00:00:00 2001
From: Stefan Zegenhagen <stefan.zegenhagen@arcutronix.com>
Date: Mon, 6 May 2013 14:39:07 +0200
Subject: [PATCH] [EDLIN] support a few more control keys

Add support for the following control keys that many users have become
accustomed to:
 - <CTRL>+W         : backward kill word
 - <CTRL>+U         : backward kill line
 - <HOME>           : goto start of line
 - <END>            : goto end of line
 - <CTRL>+<LEFT>    : backward word
 - <CTRL>+<RIGHT>   : forward word

It seems that the <CTRL>+<LEFT|RIGHT> control key sequences are
different between terminal emulators, therefore a few possible
combinations were added (similar to how libreadline is configured).
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1 parent d08b977 commit ac6baebc187c43e73f46fd8d20a262358c4b5e01 Stefan Zegenhagen committed with May 6, 2013
Showing with 30 additions and 0 deletions.
  1. +30 −0 lib/stdlib/src/edlin.erl
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30 lib/stdlib/src/edlin.erl
@@ -79,6 +79,14 @@ edit([C|Cs], P, {Bef,Aft}, Prefix, Rs0) ->
case key_map(C, Prefix) of
meta ->
edit(Cs, P, {Bef,Aft}, meta, Rs0);
+ meta_o ->
+ edit(Cs, P, {Bef,Aft}, meta_o, Rs0);
+ meta_csi ->
+ edit(Cs, P, {Bef,Aft}, meta_csi, Rs0);
+ meta_meta ->
+ edit(Cs, P, {Bef,Aft}, meta_meta, Rs0);
+ {csi, _} = Csi ->
+ edit(Cs, P, {Bef,Aft}, Csi, Rs0);
meta_left_sq_bracket ->
edit(Cs, P, {Bef,Aft}, meta_left_sq_bracket, Rs0);
search_meta ->
@@ -178,6 +186,7 @@ key_map($\^U, none) -> ctlu;
key_map($\^], none) -> auto_blink;
key_map($\^X, none) -> ctlx;
key_map($\^Y, none) -> yank;
+key_map($\^W, none) -> backward_kill_word;
key_map($\e, none) -> meta;
key_map($), Prefix) when Prefix =/= meta,
Prefix =/= search,
@@ -198,11 +207,29 @@ key_map($d, meta) -> kill_word;
key_map($f, meta) -> forward_word;
key_map($t, meta) -> transpose_word;
key_map($y, meta) -> yank_pop;
+key_map($O, meta) -> meta_o;
+key_map($H, meta_o) -> beginning_of_line;
+key_map($F, meta_o) -> end_of_line;
key_map($\177, none) -> backward_delete_char;
key_map($\177, meta) -> backward_kill_word;
key_map($[, meta) -> meta_left_sq_bracket;
key_map($D, meta_left_sq_bracket) -> backward_char;
key_map($C, meta_left_sq_bracket) -> forward_char;
+% support a few <CTRL>+<CURSOR LEFT|RIGHT> combinations...
+% - forward: \e\e[C, \e[5C, \e[1;5C
+% - backward: \e\e[D, \e[5D, \e[1;5D
+key_map($\e, meta) -> meta_meta;
+key_map($[, meta_meta) -> meta_csi;
+key_map($C, meta_csi) -> forward_word;
+key_map($D, meta_csi) -> backward_word;
+key_map($1, meta_left_sq_bracket) -> {csi, "1"};
+key_map($5, meta_left_sq_bracket) -> {csi, "5"};
+key_map($5, {csi, "1;"}) -> {csi, "1;5"};
+key_map($C, {csi, "5"}) -> forward_word;
+key_map($C, {csi, "1;5"}) -> forward_word;
+key_map($D, {csi, "5"}) -> backward_word;
+key_map($D, {csi, "1;5"}) -> backward_word;
+key_map($;, {csi, "1"}) -> {csi, "1;"};
key_map(C, none) when C >= $\s ->
{insert,C};
%% for search, we need smarter line handling and so
@@ -363,6 +390,9 @@ do_op(end_of_line, Bef, [C|Aft], Rs) ->
{{reverse(Aft, [C|Bef]),[]},[{move_rel,length(Aft)+1}|Rs]};
do_op(end_of_line, Bef, [], Rs) ->
{{Bef,[]},Rs};
+do_op(ctlu, Bef, Aft, Rs) ->
+ put(kill_buffer, Bef),
+ {{[], Aft}, [{delete_chars, -length(Bef)} | Rs]};
do_op(beep, Bef, Aft, Rs) ->
{{Bef,Aft},[beep|Rs]};
do_op(_, Bef, Aft, Rs) ->

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