Why use the keys hjkl on the same line instead of keys in a triangle like wasd for moving on video games?
Why not something equivalent with right hand, like ijkl or pl;'?
3 Answers
From http://www.catonmat.net/blog/why-vim-uses-hjkl-as-arrow-keys/:
When Bill Joy created the vi text editor he used the ADM-3A terminal, which had the arrows on hjkl keys. Naturally he reused the same keys and the rest is history!
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20Now you've got me wondering what kind of terminal the guy who made emacs had...– leeand00Commented Aug 23, 2016 at 19:09
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16@leeand00: A Symbolics LISP Machine Space Cadet Keyboard. The article explicitly talks about how the design of the keyboard influenced the design of Emacs, and it also compares it to the design of Vi with its ubiquitous Escape key, and the fact that the Escape was very conveniently located on the ADM-3A Terminal's keyboard. Well, on the Space Cadet Keyboard, there are the Control, Meta, Super, and Hyper keys which are very conveniently located, as well no less than 3 different Shift keys allowing to type over 8000 characters. Commented Aug 23, 2016 at 19:35
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12While this answer is correct as such, it sort of moves the question rather than answer it: "Why did the ADM-3A keyboard choose
hjkland not a more logical shape such asijkl?" Commented Aug 24, 2016 at 14:12 -
2@Carpetsmoker: we didn't invent keyboard arrow location logic until the late 80s upload.wikimedia.org/wikipedia/commons/3/30/… Commented Aug 24, 2016 at 14:37
Nobe4's answer is great, and explains why we use hjkl very well. However, it's really interesting to see the full keyboard, and a lot of strange things about vim make more sense when you can see the full keyboard it was designed on. For example, why does vi rely so heavily on the esc key, when it's in such a weird and uncomfortable place? This is why:
As you can see, esc is where tab is on most keyboards. ctrl is another key that is slightly awkward to reach, but in a very comfortable location on this keyboard (where caps lock usually is).
answered Aug 24, 2016 at 16:17
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1Did
vihave a<Leader>mapping? I thought that was a later invention... Commented Aug 24, 2016 at 16:27 -
@Carpetsmoker I think so, but I'm not actually sure. Vim's
:help <leader>doesn't have the signature{not in Vi}text, and it does say vi had:map(although not:noremap), so I'm pretty sure that vi had leader. Even if it didn't, I would imagine the history of the vi keyboard would at least somewhat influence the design of vim. Commented Aug 24, 2016 at 16:36 -
1It's also hard to find information on vi through google, since most of the results end up being about vim. Commented Aug 24, 2016 at 16:37
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@DJMcMayhem pubs.opengroup.org/onlinepubs/009696699/utilities/vi.html and roguelife.org/~fujita/COOKIES/HISTORY/1BSD/exrefm.pdf are good references for vi (POSIX and historical, respectively). You can also download nvi, elvis, vile, or ex-vi (ex-vi is a descendant of the historical vi) and look at what they do or their documentation. There is no
<leader>feature in vi. Commented Aug 24, 2016 at 18:23 -
Also, Vim was originally developed for the Amiga (backslash in its usual [ISO or Large Enter] position), and based on Stevie which was for the Atari ST (backslash in the lower right corner, past enter, but it didn't apparently support
:mapat all) Commented Aug 24, 2016 at 18:25
As to why these arrows were printed on these keys... it's because they could be used with the control key for local cursor movement. Ctrl-H and Ctrl-J (backspace and line feed) are obvious, and an easy mnemonic even today. Ctrl-K is "vertical tab", but was sometimes used for reverse linefeed on pre-ANSI terminals. The use of Ctrl-L for a non-destructive cursor forward was probably chosen based on its keyboard location.
You may also have noticed in the picture of the keyboard in the other answer that "HOME" is on the ^/~ key. Of course, Ctrl-^ homes the cursor (sends to the top left of the screen, or bottom left, depending on mode).
These control mappings were also used for Wyse terminals, the Kermit protocol, and were supported in some versions of PC ANSI.SYS.
Sources:
- The ADM-3A Operator's Manual, page 3-5 [pdf page 38] onward describes the control functions.
- Terminfo database for other terminals; search for
kcuf1=^Landkcuu1=^K
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1^H, ^K – very enlightening, since today I'll easily remember that ^J moves down. I was never able to remember assignment of up-down reliably.– miroxlavCommented Aug 24, 2016 at 10:57
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vimis exempt from keeping up with technological advances :3hbut rather on thej(that's why you have a "nipple" on thejkey). Reason for that is that you will usebmuch more thanhand having;accessible is handy in a lot of programming language (and with a shift, you have:which is ever more handy in Vim).