Arrow keys, `<Home>` and `<End>` do not work in `man` #5

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opened 2022-04-07 00:34:11 +02:00 by christian · 5 comments

christian commented

2022-04-07 00:34:11 +02:00

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though <PgUp> and <PgDn> work just fine

* though `<PgUp>` and `<PgDn>` work just fine

christian commented

2022-04-07 17:38:29 +02:00

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Program less is affected, too. But in ncte and pangoterm, both using an older and the same library version respectively, it works.

Program `less` is affected, too. But in `ncte` and `pangoterm`, both using an older and the same library version respectively, it works.

christian commented

2022-04-07 17:58:08 +02:00

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In less you can see the ANSI escape sequences, when holding the key long enough — not sure if sequence is complete.

Key	Escape sequence	Correct escape sequence?
←	ESC[D
↑	ESC[A
→	ESC[C
↓	ESC[B
⇱	ESC[H
⇲	ESC[F
⇱	ESC[H
↟	ESC[5~	already correct
↡	ESC[6~	already correct

In `less` you can see the ANSI escape sequences, when holding the key long enough — not sure if sequence is complete. | Key | Escape sequence | Correct escape sequence? | | ----| --------------- | ------------------------ | | ← | ESC\[D | | | ↑ | ESC\[A | | | → | ESC\[C | | | ↓ | ESC\[B | | | ⇱ | ESC\[H | | | ⇲ | ESC\[F | | | ⇱ | ESC\[H | | | ↟ | ESC\[5~ | already correct | | ↡ | ESC\[6~ | already correct |

christian commented

2022-04-08 08:36:48 +02:00

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Taking it back … ncte also does not work. Getting at least a bell.

But still, it works in pangoterm (Ubuntu version 0~bzr613-1), which uses the same version of libvterm (Ubuntu version 0.1.2-2) as NCursesPtyWindow.

Taking it back … `ncte` also does not work. Getting at least a bell. But still, it works in `pangoterm` (Ubuntu version 0~bzr613-1), which uses the same version of `libvterm` (Ubuntu version 0.1.2-2) as `NCursesPtyWindow`.

christian commented

2022-04-08 19:31:13 +02:00

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So, after some investigation into pangoterm it seems, that less communicates to the terminal to switch the standard (and thus the escape sequence for certain keys). less does the switch most likely by some termio magic.

Key	Escape sequence	Correct escape sequence
←	<ESC>[D	<ESC>OD
↑	<ESC>[A	<ESC>OA
→	<ESC>[C	<ESC>OC
↓	<ESC>[B	<ESC>OB
⇱	<ESC>[H	<ESC>OH
⇲	<ESC>[F	<ESC>OF
↟	<ESC>[5~	already correct
↡	<ESC>[6~	already correct

Problem is: Even if ncurses could handle the switch (I don't know if ), it never sees this switch, because libvterm handles it.

So the solution is to recognize the keys with ncurses and translate them to libvterm.

So, after some investigation into `pangoterm` it seems, that `less` communicates to the terminal to switch the standard (and thus the escape sequence for certain keys). `less` does the switch most likely by some termio magic. | Key | Escape sequence | Correct escape sequence | | ----| --------------- | ------------------------ | | ← | \<ESC>\[D | \<ESC>OD | | ↑ | \<ESC>\[A | \<ESC>OA | | → | \<ESC>\[C | \<ESC>OC | | ↓ | \<ESC>\[B | \<ESC>OB | | ⇱ | \<ESC>\[H | \<ESC>OH | | ⇲ | \<ESC>\[F | \<ESC>OF | | ↟ | \<ESC>\[5~ | already correct | | ↡ | \<ESC>\[6~ | already correct | Problem is: Even if `ncurses` could handle the switch (I don't know if ), it never sees this switch, because `libvterm` handles it. So the solution is to recognize the keys with `ncurses` and translate them to `libvterm`.

christian referenced this issue from a commit

2022-04-13 10:48:23 +02:00

fixes #5, touches on #8

christian closed this issue

2022-04-13 10:48:23 +02:00

christian commented

2022-04-13 11:11:26 +02:00

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Final thoughts: There is something called "keyboard_transmit mode". Which can be enabled and changes the escape sequences for various function keys. This was probably happening.

See: https://stackoverflow.com/questions/18658513/determining-escape-sequences-for-cursor-keys-canonically

Final thoughts: There is something called "`keyboard_transmit` mode". Which can be enabled and changes the escape sequences for various function keys. This was probably happening. See: https://stackoverflow.com/questions/18658513/determining-escape-sequences-for-cursor-keys-canonically