When using a TTY terminal in Linux, the scroll lock is an extremely useful key so that you can pause the output in order to read it. In most BIOS's, you can also press it to pause the info that it is giving you as well.

Many people think that scroll lock is now useless, except in Microsoft Excel, but it does have a much more useful purpose, at least in Linux and perhaps BSD.

Yet another link that Fark [fark.com] ran first, and Slashdot copied...

The Danish keymap is the same on all PC's (and Sun Boxen as well), and we need Alt Graph to access the following characters:
\@${[]}|~?

Not sure about the US keymap, but I sure as hell wouldn't want to go without Alt Graph.

You know, it's not just a LISP or Python operator... some of us use it to write in our languages. Tres frequemment, sometimes. (I'm not French, but, similarly to French, my native language uses the grave accent - just not as often.)

The tilde still has some limited use in C++ (don't know about other C-based programming languages since I don't know any of the others...yet). It's how you indicate to the compiler that this is the destructor function for programmer-defined class. That way the instructions in the destructor are automatically executed when an object of the class goes out of scope (usually used for returning dynamically allocated memory). Example: MyClass(); //CONstructor ~MyClass(); //DEstructor

It's always hard to sort through 22,000 lesbian porn pics.

Try "| sort | more" instead :)

Ditto. Fuck IBM. Whenever you finally learned:
Win+F - Search files
Win+E - File manager
Win+M - Minimize pr0n, the boss is around

the corp. buys me that Thinkpad that doesn't have it.

And ~ is essential in many URLs.

~ is also used in C for binary negation.

0xbeefbabe & (~0x04) == 0xbeefbabe & 0xfffffff8

Alt Graph is a modifier key, like Shift, Control, Meta, etc. It existed on the PC platform too. If you look at non-US keyboard maps in the old IBM DOS manuals (like version 3.30), you'll see the that one of the "Alt" keys was labelled "AltGr" (guess what the "Gr" is an abbreviation for). You had to use the AltGr key to get things like accents and stuff if you used a non-US code page in DOS.

ISTR that AltGraph+Help did something on older Sun machines, but I can't recall what.

it's also the bitwise-NOT operator.

say char boing = 0x55; // 01010101
char gniob = ~boing; // 10101010

# mkfifo booda
# cat text > booda

in another window:

# cat booda > somefile

voila

In BSD, using the arrow keys with scroll lock on is the equivilant of shift+PgUp,PgDn in Linux.

For example, una says the Macintosh extended keyboards have a scroll lock key. It does not.

Yes it does. It shares the same keycap as F14.

I have news for you, and its name is ^S and ^Q! Sing it loudly from the mountaintops!

P.S. this works places other than Unix also.

'clip' is not a program which comes default installed with WinXP. Try it and see.

You must have it installed from somewhere else, or as part of the admin pack or whatever. Its obvioulsy just a program which puts the stdin input into the clipboard, pretty useful, but not included by default.

In OSX it is ls | pbcopy

I have one of these laying around. Those three keys are labelled F13-F15, but in smaller letters say "print screen" "scroll lock" and "pause" respectively

Now, it might be that some of the newer mac keyboards don't have scroll lock, but the original ADB extended keyboards did. For example, I have a USB spanish mac keyboard that doesn't have those extra labels.

in X xsel, its not part of X, but clip is not part of default win install either

the windows example was piping output from a command line application into the system clipboard (as in copy/paste). Your example is quite different.

get xclip http://people.debian.org/~kims/xclip/, install, then

$ ls | xclip -i

does what you'd expect.

Use Ctrl+Arrow keys to scroll in this situation. The insertion point will probably be moved to the edge of the visible area.

Since everyone hear has totally missed the boat I'll chime in. The concept of a Scoll lock is indeed alive and well today. Try the following on your Unix computer: run some command that spews text to the screen in a terminal window (e.g. fs_usage or du /) now while its scrolling type control-S. it scroll locks. Now type control-Q to resume the text output.

this dates back to the teletype and is enshrined in the ascii alphabet as Xon and Xoff. Originally it was intended not as a scroll lock but as a way for a teletype or printer to not overflow its fixed hardware buffer. The communication baud rate could easily out pace the tele type printers print speed. when the hardware buffer was nearly full it would send an X-off (contol-s) to the sender to pause its communications. When the buffer was printed the teletype would send a X-on back to the sender to resume spewing.

There was no need for scoll locking functionality on a teletype printer since you could just hold up the paper and look at it back as many lines as you wanted.

but when dumb video terminals came along the terminals could print as fast as the data came in the X-on and X-off functions had little use as a communications protocol, but Now they were useful to humans as a scroll lock. they had at most 40 lines of text and once you scrolled off the top of the screen, you lost that line forever. There were no "windows" or "scroll bars". So you had your fingers poised over the contrl-s key to halt the text from flowing off the screen.

finally along came the PC and Microsoft messed with all the unix converions in their VMS/CPM ripoff called dos: so you could not be sure that control-S would actually work. In part this was because DOS was not really multitasking. programs could take over the OS and capture all the interupts and put hooks directly into the keyboard handler. Since there were no Menus and the "alt" key had not come into its standard defintion yet, the control keys were premium realestate for programs to hook functions into.

thus there was a need for another semaphore. So things like scroll lock and sysRequest, and print screen got added. So yes virgina you can blame MS for these keys as valuable male breasts or an appendix.

Correct. clip isn't built in.

Clip is one of the utilities from http://www.cmdtools.com/ [cmdtools.com].

Well, the clipboard is a property of the environment, rather than the OS. But there's certainly at least one environment that allows this: GNU screen [fu-berlin.de].

Screen has a concept of a buffer file that can be used to store or load the clipboard. The name of this file is defined in your screenrc, so it can vary from system to system, but it's often called /tmp/screen-xchg or (better for multi-user systems) ~/.screen_exchange. The keystroke ^A< reads this file and ^A> writes it; ^A> will also flash up a message telling you what the name of the file is (for example, Copybuffer written to "/tmp/screen-xchg" ).

So what you do is:

$ some-command > ~/.screen_exchange
^A< (copybuf)
screen responds "Slurped 2323 characters into buffer"
^A] (paste)

And there you have it.

In every version of Windows since 3.1 pressing Print Screen will copy a screenshot of the entire screen to the clipboard. Pressing Alt + Print Screen will copy an image of the current active window.

Una Persson??

Well call me Catherine Cornelius and break out the psychotropic lesbian porn fiction...

Well it is true to the spirit of Moorcock. Just look at the cover art [eclipse.co.uk].

Ok, so it is a touch off-topic, but I was stunned to see a literary(sic) reference in a /. link

Q.

Not really. The idea, I expect, is that the key is there to allow someone to not have to use a mouse at all, for certain things. ie: Move through a list of files in a directory, hit this key, select open with, or whatever.

It's useful if you are typing, with your hand away from the mouse, and want to do a right click on th highlighted item.

Really...

Enclosing statements in backticks causes the string to be executed at the shell level and the resulsts stored ina string. You can do this in bash, Perl, PHP, and a myrid of other lanuages. eg type "echo `ls`" at the prompt. Then again I am sure most everyone knew this already

If I recall correctly, back in the days of openlook, the props key was used to bring up the properties menu for a window. That's as much as I can remember.

From syscons(4) in FreeBSD:

Back Scrolling
The syscons driver allows the user to browse the output which has
``scrolled off'' the top of the screen.

Press the ``slock'' key (usually ScrllLock / Scroll Lock or Pause on many
keyboards) and the terminal is in the ``scrollback'' mode. It is indi-
cated by the Scroll Lock LED. Use the arrow keys, the Page Up/Down keys
and the Home/End keys to scroll buffered terminal output. Press the
``slock'' key again to get back to the normal terminal mode.

The size of the scrollback buffer can be set by the SC_HISTORY_SIZE
option described below.

The "| clip" thing is not a WinXP thing. It's a 32-bit command line tool created by Dave Navarro.

cmdtools website [cmdtools.com] "clip" is near the bottom of the page

clip.zip [cmdtools.com] direct download

And, as you might expect, pbpaste lets you access what's currently on the clipboard.

In BSD

NO! Not in "BSD", ONLY in FreeBSD... FreeBSD is not the end-all, be-all BSD, thank you very much.

In theory, after running "apt-get install xclip" you can do things like

producer | xclip -i

and the primary X selection will be loaded up with the output, all reading for middle-clicking. Likewise, you can sweep a bunch of text and use it with

consumer `xclip -o`

Other options let you use other clipboards, etc.

In practice, you can't just apt-get it. You have to apt-get the source, apply the content negotiation patch [debian.org], and run buildpackage yourself. Then it works perfectly. (I have no clue what content negotiation means, but apparently kde wants it.)

The SysReq (or "System Request") key is still heavily used in the as/400 world for job management on the system console. Using the SysReq key, you can send different signals to whatever current job was running

Think of it as a key dedicated to the unix 'kill' command.

~dlb

I didn't see anyone comment on this, but the SysRq hooks to the Linux kernel. It allows the user to send commands to the kernel like sync, reboot, etc.

It was used to lock the cursor in place, and the up and down arrow keys scrolled the entire screen, leaving the cursor locked.

I'm not entirely certain what article you thought you read, but according to Una:

The main intent of the Scroll Lock key was to allow scrolling of screen text up, down and presumably sideways using the arrow keys in the days before large displays and graphical scroll bars.

According to you, it sounds like Una got it right at the start.

RTFA

I imagine open files are tied to the "true" paths:
multi(0)disk(0)rdisk(0)partition(1)/window s/system 32/ntoskrnl.exe
etc, etc, etc...

The C: drive thingies are just useful for the Win32API, so opening new files off that drive won't work, and explorer will probably fail in mysterious ways later on, if the C: is mentioned anywhere in the registry where it might be used to dynamically load some view or file operation.

As you might expect, drives letters are just places where to start a mapping to a mounted filesystem (which is internally identified with a GUID, like everything else, the drive letter has no significance). Windows only needs C: to boot and load programs, but if you aren't opening files, you don't need it.

Also, in WinXP or higher, you can pipe text into the copy buffer. I use this all the time.
type reallybigfile.txt | clip

Microsoft Windows XP [Version 5.1.2600] (C) Copyright 1985-2001 Microsoft Corp. C:\Documents and Settings\revmoo>echo moo | clip

'clip' is not recognized as an internal or external command, operable program or batch file.

Care to elaborate?

Can anybody please tell me that the "blank" key next to the help button on a Sun keyboard is used for?

Mac OS X can do this via pbcopy and pbpaste, the pb standing for the NeXT-ism "pasteboard," or what Mac users normally call the clipboard.

For example, is you issue the command:

cat somefile | pbcopy

the clipboard receives the contents of somefile, whereas if you type:

pbpaste > somefile

puts the contents of the clipboard into the file somefile.

On keyboards in general, most keys generates two characters. This is fine for English, not using any letters besides A-Z or any accents as far as ASCII is concerned.

However, for many European languages, there are additional characters, like a+ring (U+0035) in Swedish, and accented characters, like e+acute (U+00E9) in French. Since back in the days of XTs, there were only 83/84 keys to go around, they made some keys produce a third and sometimes fourth character. These were accessed by pressing Ctrl and Alt for the third char and Ctrl, Alt and Shift for the fourth char and then the key.

At some point, it was (rightfully) decided this was unnecessarily clunky. Keyboard BIOSes/drivers were changed to support the Mac-style input of accent + character to generate that character accented. That still left the 'standard' for older keyboards to be backward compatible with, and other chars that didn't fit that pattern.

So when the 101/102 key keyboards came out, for European languages that changed the right Alt key to Alt Gr, or alternate graphic. (For some languages it had a different abbreviation, like Alt Car). This allowed typing Alt Gr plus one of the 3- or 4-character keys to access the 3rd (and with Shift, the 4th) character. Still a pain, but less so than a 3 or 4 finger salute to get a single character.

Actually, check this [sysinternals.com] cool hack out.

Mind you, this is not a registry thing because you actually need code to run it. With this, caps lock will go uppercase, and CTRL will release the lock.

Wow, that looks exactly like a spellcheck function in PERL! :)

Obviously the scroll Lock key (next to the panic button key) is for console switching.

On Belkin KVMs:
[Scroll Lock]-[Scroll Lock]-UP

it's because Sun Type 6 keyboards are made for both Suns and Linux boxes they ship, and on Linux boxes it's the escape key. The just change the key covers.

Here [win.tue.nl]'s a list...there are some other interesting ones on there too, like that weird Fn key on laptops.

Not to mention the SysRq key still in use on Linux for debugging---if you enable CONFIG_MAGIC_SYSRQ (Linux 2.4) or CONFIG_SYSRQ (Linux 2.6).

I really doubt that ``it's days are numbered.''

The "Alt Gr" key is used for us foreigners to reach seldomly used charatcers like @$ (Alt-Gr 2, 3 and 4 respectively), or {[]} (Alt-Gr 7890) or | (alt-GR `) or \ (alt-GR ). And more important, Alt-Gr e is the Euro character. You know, the european dollar, way stonger than the US dollar.

On the other hand, we get often used charatcers like aeoa as primary keys, and have access "# with Shift + 2, 3 and 4.

This is all based on a danish keyboard. Some people have grown beyond US-ASCII (7-bit crap)

I read it, but that description was completely unclear. You can move text up, down, and sideways using the cursor too. Una never was a very clear writer, she's more interested in her lesbian porn than clarity. She focuses on minutiae like her incorrect assertion that ScrlLk was intended for pausing, and ignores its original design function. I repeat: The ScrlLk key is a vestige of IBM WPS, it should really be called Cursor Lock because it locks the cursor, not scrolling.

In Window Maker, 'wxcopy --help' and 'wxpaste --help' for help on using those.

I'm afraid I don't know about the others. Anyone? Anyone?

" This is one of my major "wow that is a PITA" points about Linux.

WHERE ARE MY HOTKEYS???"

Wherever you set them.
I have alt+c close current window, alt+k,c to sigkill it, alt+mwheeldown/up to cycle through tabs in my current pane (I use ion. I'll provide screenshots if someone asks). Then theres the GNU ReadLine shorcuts that a lot of apps respect(most because they actually use ReadLine, then the rest just because theyre standard.

^A - begining of line
^E - end of line
^K - delete text from cursor to end of line
^U - delete text from cursor to begining of line
^V - insert raw char regardless of other bindings

Theres plenty more, see man ReadLine. They're all configurable of course.

All the mysterious keys are there for you to remap using xmodmap! And having a spare one left over is allways good if a key fails (as a result of piping tea through yourr keyboard). And of course, the windows-key is in the correct place of a meta key, so you could be a better emacs-user in just minutes! And when talking about SysReq, it really is a request to the system, if you gave Magique SysReq compiled in in your Linux-kernel - then press Alt-SysReq-key where key is b to reboot, s to sync disks and r to remount all disks read-only. And this works even if some user-space program fucks up your screen and keyboard...

The Scroll Lock was also used by a DOS TSR known as ANSI. When loaded, it allowed scrolling of the entire screen history when the Scroll Lock was on. When you dir a huge folder, you could hit scroll lock and use the arrow keys to navigate the entire list of files. More useful than dir /p...

The Print Screen/SysRq key was used in Dos to send the current screen of text directly to lpt1: (your printer), hence the name "Print Screen". In Windows (all the way back to Windows 3.x), Print Screen executes a screen capture (without the mouse cursor) and puts it on the clipboard. Alt+PrintScreen copies just the current window.

In addition to what was said in the article about Pause/Break, pressing it _during_ a dir or other scrolling text operation will halt the screen. (This includes during booting before the OS loads.) Press any key to continue.

As for the `/~ key? Still haven't found a useful function for it other than typing a ` or a ~.

And the |? That one serves just about the same purpose to me as the "Context Menu" button on many newer keyboards, which is to say, none.

windows will remount the drive automatically, whenever there is an access on it. Volumes and file systems are very much the same, unlike in unix environments.

Unmounting forces a flush, so it can have a purpose though. Heck, even trying to lock a volume / file system will flush it for you. How's that for a sync :)

Ah... in NeXTStep it was called the Pasteboard?

For people who don't speak english, Alt Gr is pretty useful, as it lets you type accented characters. In EU countries, it is also used to let you type the Euro symbol - Alt-Gr+4 on UK and Irish Keyboards, Alt-Gr+E on most others.

You apparently have never copy-pasted something very long from terminal window... Sure you can scroll, but it's still pita if it's even moderately long.

Try irfanview [irfanview.com] an excellent image viewer, with automatic resize and slideshow!

I have noticed that ALT+0xxx give you the Windows character xxx, but alt+xxx gives you the approximate DOS character xxx. The box-drawing characters (e.g. used in WinDOS ports of NetHack) come out as +|-=_ or similar.

Yes, there's a class named NSPasteboard in the AppKit. Unfortunately, apple has not seen fit to write a manpage for "pbcopy", so I'm not sure if there is a way to individually access the more specialized pasteboards--MacOSX has at least five of them.

I use the ScrLk key to make my Belkin KVM switch change displays. If I hit it twice (it beeps) then hit the up/down key, it goes to the next/previous display. And I can even hit a number rather than an arrow key and it goes straight to the terminal plugged into the number key I hit. And if I hit the space bar after it beeps I am presented with an OSD for the KVM switch.

If I hit Ctrl then hit Esc (not to be confused with pressing them at the same time) on my Black Box KVM switch, I get an OSD that allows me to navigate to the terminal I want (very nice when you have 30 servers on KVMs).

Maybe CSHOW? It had a palette-rotation feature which was good for viewing fractals (they were all the rage back then).

There is a Windows application that makes Scroll Lock perform its original function on most applications (not just Excel).

It's here [scroll-lock-lives.com].

(Plug alert: I work for Platonix; this is a toy).