Why was '~' chosen to represent the home directory?

http://unix.stackexchange.com/questions/34196/design-question-why-was-chosen-to-represent-the-home-directory

by rawland • 14 years ago

413 153 14 years ago

unix.stackexchange.com

sdoering2• 14 years ago

I really liked the additional info on the vim-navigation-keys. Really interesting to see, how the design of specific hardware shaped the "how to use" for generations to come.

I really have my problems, to wrap my head around "hjkl", as there is (imho) no logical mnemonic for the directions. It is sadly just "learn by rote".

ximeng• 14 years ago

h and l are obvious for left and right as they're on the left and right. Lower case j goes below the baseline, so down, k is solid at the top so up.

tome• 14 years ago

Another question: why shift your right hand one place to the left from its normal position on the home row?

evincarofautumn3• 14 years ago

I would prefer JKL; to HJKL because my index finger typically rests on the J. Then again, I am an Emacs user, so what do I know?

anonymouz4• 14 years ago

Put this in your .vimrc:

  " Disable arrow keys
  noremap <Up> <nop>
  noremap <Down> <nop>
  noremap <Left> <nop>
  noremap <Right> <nop>

You'll have one or two frustrating days, but after that your muscle memory will take care of remembering "hjkl" for you.

sdoering2• 14 years ago

I know, did this at home and started yelling at my laptop shortly after. Got better, am using the keys nowadays, when using vim.

But non the less, the logic didn't register with me. (something like clockwise/counter-clockwise, or anything remotely recognizable ;-) )

martinp• 14 years ago

Another vote for this method. This is the only way I managed to train myself to use hjkl when I first started learning Vim.

I also disabled Home, End, PgUp and PgDown:

  noremap <home> <nop>
  noremap <end> <nop>
  noremap <pageup> <nop>
  noremap <pagedown> <nop>

SiVal3• 14 years ago

Every keyboard now has a set of hardware arrowkeys sensibly arranged in an inverted-T, where up means up, left means left, etc. Since everyone is used to that arrangement without any mental effort, macho vim types tell you to force yourself to write with your feet basically to show how hardcore you are. They tell you to use your customization ability in .vimrc to block the sensible arrangement in order to force yourself to learn a ridiculous one that has no advantage other than being the one that we old-timers had to learn before there were sensible arrowkeys.

I used that arrangement back in the 1980s myself, but when keyboards evolved, so did I. I remapped the movement keys to match the other movement keys (arrowkeys).

If you're going to go to the effort of customizing your vim to force yourself to learn a new keyboard arrangement, customize it so that the movement keys are ijkl instead of hjkl, so that both of your sets of arrowkeys are in the same, natural, modern, inverted-T arrangement. Then you don't have to deactivate those real arrowkeys, because there won't be any temptation to use them with the ijkl keys in the same arrangement and easier to reach.

"Oh, no!" people half my age will shriek. "Then what happens to the 'i' key? This would be impossible." Just use the now-unused key on the left ('h') for your insert-on-left. Reach left to insert on left. There, easy.

Funny how those who insist that YOU should relearn something as fundamental as the entire inverted-T arrowkey structure built into the hardware of every keyboard and used by almost all apps on all platforms including kids' game boxes find relearning a single, arbitrary 'i' key such an insurmountable obstacle to themselves.

But what if you have to use a copy of vim on a machine without your customized .vimrc? Sorry, but that's just an argument against ANY useful customization of vim. It's just not a problem, because the real arrowkeys on the keyboard are in the arrangement you're used to using on the ijkl keys. Just use the real arrowkeys temporarily or copy over your .vimrc. I've done it for years.

But what about other editors that have a vi mode? What about something like zsh with a vi mode? These things can be remapped to match your .vimrc unless they only offer a couple of keys, in which case they can be treated just like all apps with their own couple of local keyboard shortcuts.

Really, if the standard advice is, "You'll have one or two frustrating days, but after that your muscle memory will take care of remembering "hjkl" for you," then you can take your own advice and keep the inverted-T muscle memory you already have for the movement keys and reduce your task to learning a single 'h' key for insertion, and save the next generation from this nonsense.

If a 30-yr user of vi like me isn't stuck with the historical accidents of the past, why should new users have to be?

nonamegiven2• 14 years ago

Although this can be helpful to force some people to learn hjkl, you may want to remove this after awhile.

I use whatever my hand happens to be closer to. 85% of the time that's the home row, hjkl. But if my hand is closer to the arrow keys I'll use that, and if my hand is on the mouse I'll use that.

gmrple• 14 years ago

My preferred method is a couple hours of Nethack.

oftenwrong• 14 years ago

I re-purposed mine for buffer switching:

    " Arrow keys set up for easy buffer switching
    nnoremap <left> :bprev<cr>
    nnoremap <right> :bnext<cr>
    nnoremap <down> :buffer #<cr>
    nnoremap <up> :buffers<cr>:buffer<space>

ars• 14 years ago

My fingers still remember the Apple II keyboard arrows keys: Left, Right, Down, Up.

http://jwvideo.free.fr/ImagesMac/AppleII/Apple%20II%20int%C3...

I've always thought that was so much better than the inverted T on PC keyboards, since you can press all the keys without moving your fingers - much faster for games.

yen223• 14 years ago

I also have problems with 'hjkl'. I could never tell which is up and which is down. If it were up to me, the navigation keys would be mapped to WASD instead.

juan_juarez3• 14 years ago

You could do that if you wanted.

Xion• 14 years ago

When starting vim (any editor, really) you usually begin at the top. So you want to go down first...

Oh, this `j` key has an inset to distinguish it from the rest. Surely this means I need to press this one!

(You can easily figure out the three other keys from there).

oneandoneis2• 14 years ago

What worked for me was:

H & L are left & right - fairly intuitive, leftmost is left, rightmost is right

J looks kinda like a down arrow

That leaves K, which must be up by process of elimination :)

lobotryas• 14 years ago

I memorized HJKL thusly: • H and L are leftmost and rightmost keys, therefore they move the cursor left and right respectively • J kind of looks like it's pointing down • This only leaves K as the up arrow (the only remaining choice)

kennu• 14 years ago

I remember them because Ctrl-J is newline (moves down), and the rest are obvious after that.

johncoltrane• 14 years ago

Learn other motions instead (eEbBwW/?fFtT and so on).

Once you have integrated them in your workflow, you'll wonder why you even got into the trouble to force yourself to use hjkl instead of the arrows.

gnosis• 14 years ago

The best way to learn the hjkl movement keys is to play a game like nethack.[1]

[1] https://en.wikipedia.org/wiki/Nethack

koralatov6• 14 years ago

Seconded.

Remapping the movement keys in Worms Reloaded also helped massively, though did result in me getting completely thrashed for the first twenty or thirty matches I played.

kibwen• 14 years ago

This was my thought when I first tried learning Vim, but I quickly realized that my right-hand home row position for roguelikes is one key too far to the left, meaning that I either had to unlearn those years of DCSS or else teach myself how to type all over again. Not to mention the incessant frustration of unintentional jumps, yanks, and undos when all you're trying to do is move diagonally.

Steuard• 14 years ago

Yeah, but I always played with number_pad enabled, so I never picked it up. (And then I wound up being incapable of playing the game sensibly on my laptop, alas: no diagonals.)

nonamegiven2• 14 years ago

hjkl: just learn them.

These four keys are the most basic thing about vim. Yes there doesn't seem to be much to remember them by, but for these at least, there doesn't need to be. Just muscle through it as long as it takes. It won't take long if you're using vim regularly. Soon you won't think about it, you'll just think "up" and you'll be up a line without consciously thinking "... um ... k".

There are ways to get around these four: arrow keys, macros, whatever. Don't. Just learn them.

Bonus, those keys show up in other vim-like command interfaces, including bash and other shell command line shortcuts. And if you use .inputrc, they'll show up in database and language repls and similar environments.

Just learn them.

DanBC2• 14 years ago

I'm surprised no-one has knocked together a tiny "game" to teach hjkl.

Display a big arrow, grab an input, make a nice boop noise if it's right and a nasty beep noise (with a graphic flash) if it's wrong. Keep score of how many key presses were right, and average time for each press.

kps2• 14 years ago

Two of the four are simply the standard ASCII control characters:

· Control-H is Back Space: it moves the cursor one position left.

· Control-J is Line Feed: it moves the cursor one line down.

The other two seem to be arbitrary on the part of the ADM-3A designers, and having Control-L (Form Feed) perform cursor-right rather than clear-screen seems a bit dubious, but given their constraints and the desire to keep all the motions together, it's hard to argue for any different choices.

agumonkey• 14 years ago

Can't find the source saying hjkl ascii code is a simple bit-shift operation away from tty arrow code.

Sukotto• 14 years ago

  "hjkl", as there is (imho) no logical mnemonic for the directions.

left: "h" is leftmost in the group

right: "l" is rightmost in the group

down: "j" extends down below the baseline

up: "k" extends up to the topline

dllthomas• 14 years ago

I'm no sure how much it'll help, but:

h: move left ctrl-h (which is backspace in ASCII): move left a space while doing something

j: move down ctrl-j (line feed): move down a space while doing something

Unfortunately, this doesn't extend to k (vertical tab) or l (form feed), but... maybe it's helpful?

If you need to practice, play robots or nethack...

cpeterso• 14 years ago

My mnemonic for J/K is that my index finger (on J) is "pointing down".

(I started to write "and my middle finger (on K) is pointing up", but then I realize that an upward-pointing middle finger means something entirely different.. <:)

chousuke• 14 years ago

I learned to use hjkl(yubn) by playing Crawl on a macbook which doesn't have a numpad so it was impossible to move diagonally otherwise.

Nowadays I don't even need to think about using any of those keys for moving around. In fact, I use them in pretty much every application that supports them, including Firefox (with pentadactyl) and less.

saddino• 14 years ago

Ah yes, I used the baby blue version. Probably my favorite terminal until the HP2621a (which had a great character set, "modern" housing, and nice loud beep). Since I used the line editor to program I only really used HJKL as cursor keys in rogue. :-)

shmerl3• 14 years ago

Still using Sun Unix keyboard with tilde on the right, and no obnoxious Windows keys ;) Control in the middle row on the left is also helpful in order not to stress the pinky.

wereHamster• 14 years ago

You can remap keys in modern operating systems. Any sane person will remap capslock to something they use more often (eg. ctrl or alt). Who needs capslock anyway?

koralatov6• 14 years ago

YouTube commenters, and my boss. I haven't managed to break him of the habit of activating Caps Lock, pressing the key for letter he wants capitalised, then deactivating Caps Lock again.

rootbear• 14 years ago

I used to think the same way until I suffered neurological damage that affects the sensory nerves in my fingers. Holding down the shift key while I type some all-caps text, like "STUPID_SHOUTY_MACRO_NAME", is uncomfortable, so I now find the caps lock key useful. It would be nice to have it as a control key, but I would want some other way to activate the caps lock function. Maybe a double tap on the shift key, like on the iPhone keypad, would work.

finnw• 14 years ago

> Who needs capslock anyway?

C and Java programmers.

arethuza2• 14 years ago

Does your Sun keyboard have a "Stop" key? I seem to remember that for about 99% of the Sun machines I encountered hitting "Stop A" was pretty obnoxious.

shmerl3• 14 years ago

Yes, all those extra keys work with OpenSolaris and OpenIndiana. Alas, they don't produce any scan codes with Linux. They are located in a separate area on the left, so they don't disturb your workflow.

http://docs.oracle.com/cd/E19683-01/806-6642/images/BR.unix....

mst• 14 years ago

What's even more fun is that depending on your LOM configuration -removing- the keyboard can send a Stop-A.

This is not entirely hilarious when a junior sysadmin 'tidies up' the keyboards connected to the main database server (and even further from funny when the slave is currently down for maintenance ...)

mturmon2• 14 years ago

It was also the quickest way to get root. Stop-a would drop you into the monitor, then b -s to boot into single user mode. Congratulations, you are root, now just edit /etc/passwd to put in a new user "toor" with uid 0, and reboot into multiuser mode.

greyfade• 14 years ago

The Happy Hacking Keyboard has a similar layout, with Esc in the upper-left where it belongs, Ctrl in the middle-left where it belongs, and tilde in top-right where it belongs. :)

DelvarWorld• 14 years ago

100+ upvotes for a lmgtfy answer :(

evincarofautumn3• 14 years ago

Sometimes people just don’t know how to search for the topic that interests them. Asking the question is the only way they will find the answer. In that case, adding a well-framed presentation of your better-informed search results, along with some links, is actually a net gain. Search engines can now index your answer and ultimately enable fewer questions like this.

DanBC2• 14 years ago

That wasn't a lmgtfy answer. It was a constructive link to an encyclopaedia article, with a relevant quote from that article, and a relevant image. There were also links to other sources of information.

lmgtfy is hateful because it often links to the same search that the asker has previously done, and returns the same not-useful hits. But the answerer doesn't check the returned hits, and just smugly slaps lmgtfy in to "teach" the asker a lesson about searching before asking.

yeison• 14 years ago

Thanks for this post.

rawland• 14 years ago

Welcome! :-)

Actually, I stumbled over that question during my quest of unifying my keyboard-layouts (Mac=Work and Linux=Private) via xmodmap.

chimeracoder4• 14 years ago

Is that even possible? No matter which way I've tried mapping the keys on OS X, something just can't be placed in the right spot on the keyboard - mostly because many uses of CTRL are placed on the equivalent of Mod-4 (the Command key).

Unless you're just trying to simulate an Apple keyboard configuration on Linux, that is.

johnlinvc• 14 years ago

The ctrl location on that old machine is much more handy. I've changed my caps lock to ctrl for years.

koralatov6• 14 years ago

Same here. I do, however, hate that most keyboards have a `stepped' Caps Lock key, presumably to stop people accidentally activating it when they type an `a'. Thankfully, my laptop doesn't, and neither does my keyboard at home.

Symmetry2• 14 years ago

The escape key is also in a better place.

tracker13• 14 years ago

Considering I started on the early PCs (XT), I'm too used to the CTRL key where it is... I have a real problem on lenovo, and similar keyboards where the Fn key is in the corner. I also discovered, I favor the right shift, which makes a lot of mini/htpc keyboards a pain... the one I am on right now has the shift to the right of the up arrow.

ck2• 14 years ago

On a side note, stackexchange is getting pretty impressive.

http://stackexchange.com/sites

Aardwolf2• 14 years ago

Why oh why did the ADM-3A keyboard not use a gamer configuration for its arrow navigation keys. What a noob designed that!

He could have gone for wasd or ijkl. But he had to go with hjkl!

Anyway, the fact that j looks like a down arrow is a very good thing that makes me remember it and allow me to play nethack.

koralatov6• 14 years ago

Even worse, it didn't use Cherry red switches, and it looked like crap. Where were the bright red LEDs, macro shortcut buttons, and elaborate wrist-rest?!

Aardwolf2• 14 years ago

Cherry red, the linear ones? Why not Cherry brown or blue?

dkhenry2• 14 years ago

What does the "Rub" key do ?

shaurz• 14 years ago

Delete a character i.e. "rub out", presumably.

dkhenry2• 14 years ago

Is that a carryover from the typewriter days ?

killahpriest• 14 years ago

Rubber is the British English word for eraser.

atuladhar• 14 years ago

I use vim a lot, but as I was reading this, I realized that unless I was in a vim session (or pretended that I was in one), I couldn't remember which of the hjkl keys mapped to which direction.

grimgrin• 14 years ago

I think playing Crawl a ton is the only reason I remember so well. But playing too much crawl makes me think I can also move diagonally in vim (yubn).

ebbv• 14 years ago

So this is what HN has come to eh? Just random trivia links. Cat pictures can't be more than two weeks off.

juan_juarez3• 14 years ago

The link content is below par for HN but the tangential discussions that come from it make up for it.

breck• 14 years ago

I disagree. This is a very interesting data point representative of a broader pattern:

Why do we use X?

Because N years ago, the environment looked like E1, and so X made sense. Then, people got used to X as a convention, and even though our environment changed to E2, we still use X because of network effects.

A great way to improve the world is to understand where X came from, understand how E2 differs from E1, and then invent Y to better fit E2.

The hard part is that Y needs to be significantly better than X so that you can get people to switch given that X has stronger network effects.

B-Con• 14 years ago

Badly off-topic, but I found it amusing that the user asking the question was "Lelouch Lamperouge". The juxtaposition of Lelouch and "home" brought that series back into my mind full-force.

robomartin3• 14 years ago

Funny how all roads lead to a discussion of the merits of vi/m.

At least some of you now understand that these tools were designed as you see them today because they were dealing with crippled hardware (from today's vantage point). There was no magical study on keystroke efficiency at the inception. They had lemons and made lemonade.

Now, quit arguing and get back to reading Facebook!

Yup, that's me ducking in the corner.

stcredzero3• 14 years ago

HJKL is madness. It's more proof that "The Inmates are Running the Asylum" when it comes to usability. We programmers are so much more apt at remapping functions to arbitrary inputs/symbols that we continue to put up with things like this, decades after the reason disappears. This is also why we need to make special efforts at understanding non-programmer users.

alecdbrooks2• 14 years ago

I do agree that "we need to make special efforts at understanding non-programmer users." But this isn't a good example since Vim is a specialized editor mostly recommended for programers. If the general-purpose text editors (and word processors) required you to use HJKL, you might have a point. (EDIT: I misunderstood stcredzero's argument. See stcredzero's comment below.)

It's also true that functions can be mapped to arbitrary inputs and systems. But I think there's value in learning HJKL rather than remapping them:

1. They're on the home row, giving a slight speed benefit for these commonly used actions.

2. You get used to the movement keys that will be the default in any copy of Vi/m and quite a few other tools. (HJKL, along with WASD and dedicated arrow keys, is probably the most common mapping of left, right, up, and down to keys on a keyboard.)

rubyrescue• 14 years ago

i have tried both and hjkl is just faster. it's "madness" the same way having 88 white unmarked keys on a piano is "madness" to someone who doesn't play.

randy909• 14 years ago

Looks like it also explains why caret (^) was chosen in regex and vi to mean "beginning of line".

dbbolton• 14 years ago

So why was '~' chosen over '^'?

kragen3• 14 years ago

If I recall correctly, control-^ (i.e. 0x1e, aka control-~) would move the ADM-3A cursor to the "home" location on the screen (i.e. the top left) if sent from the host. If you were talking to a host that was echoing your keystrokes (and maybe if you set a DIP switch for half-duplex mode?) then typing control-^ (aka control-~) would do that too.

The terminfo entry seems to confirm this (apt-get source ncurses-term && less +/^adm3a ncurses-5.9/misc/terminfo.src):

    adm3a|lsi adm3a,
        OTbs, am,
        cols#80, lines#24,
        OTma=^K^P, OTnl=^J, bel=^G, clear=\032$<1/>, cr=^M, cub1=^H,
        cud1=^J, cuf1=^L, cup=\E=%p1%{32}%+%c%p2%{32}%+%c,
        cuu1=^K, home=^^, ind=^J, kcub1=^H, kcud1=^J, kcuf1=^L,
        kcuu1=^K, rs2=^N,

I think the speculations about ^ in regexps coming from the same source are misplaced, because I think the ed editor was already using ^ to mean "beginning of line" before there were any CRT terminals.

The ADM-3A had direct cursor addressing, as referenced in the "cup" capability in the above terminfo entry, so the "home" feature was, strictly speaking, redundant. As you can see from the simplicity of the terminfo entry (notably its almost complete lack of escape sequences) logic was aggressively minimized in this termainal. I seem to recall from glancing inside the ADM-3As I bought at auction in my childhood that it was built almost entirely out of discrete 7400-series logic, so every extra control character involved adding several chips.

In light of this, I suspect that the "home" feature may have been retained for backwards compatibility with something else — maybe the ADM-3? But the ADM-3 terminfo entry doesn't mention "home", so I don't know.

More details about the ADM-3A can be found at <http://manx.classiccmp.org/details/11,5618>.

Why was '~' chosen to represent the home directory?

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