Create a "hacker typer" program that renders its own source code
HTML & JavaScript, 123
<head></head><body onload="s=(a=document.all)[i=0].innerHTML" onkeyup="a[2].textContent += s.split(/(?= )/)[i++%6]"></body>
This works similarly to hacker typer, but with its own source code. Let me know if I've misunderstood the rules.
And here's a styled version (170 characters):
<head></head>
<body style="background:#000;color:lime" onload="s=(a=document.all)[i=0].innerHTML" onkeyup="a[3].textContent+=s.split(/(?=\s)/)[i++%6]">
<pre></pre></body>
I've made a demo. It's modified because JS Bin adds a lot of extra code, but the general idea is the same.
bash, 51 58
for w in $(<$0);do read -sn 1;printf -- "$w ";done
Perl + Term::ReadKey, 56 bytes
use
Term'ReadKey;ReadMode
4;open
0;ReadKey,print
for
<0>
Thanks to ThisSuitIsBlackNot for the original inspiration, and to primo for suggesting open 0 and <0>.
Note that the newline after for is actually unnecessary, except that I need to include one extra newline somewhere to bring the whitespace count up to the specified minimum of five.
Also note that, like ThisSuitIsBlackNot's submission, this program requires the Term::ReadKey module from CPAN. On Debian / Ubuntu Linux, this module, if not already present, can be easily installed with the command sudo apt-get install libterm-readkey-perl.
Also, to save a few characters, this program does not restore the input mode to normal on exit, so you may find yourself unable to see what you're typing afterwards. Executing the shell command stty sane or reset should fix that. This issue could be fixed, at the cost of 10 extra bytes, with:
use
Term'ReadKey;ReadMode
4;open
0;ReadKey,print
for<0>;ReadMode
0
Bonus: Pure quine, 81 bytes
$_=q{use
Term'ReadKey;ReadMode
4;ReadKey,say
for
split$/,
"\$_=q{$_};eval"};eval
Again, the newline after the comma is only needed to meet the five whitespace minimum.
Unlike the 56-byte program above, this version doesn't actually need to read its own source code, since it's based on a quine — specifically, on this quine:
$_=q{say"\$_=q{$_};eval"};eval
The nice thing about this quine is that it can easily carry an arbitrary "payload" within the q{ } block, without having to repeat it. While it can't quite beat <0> in shortness, it does get pretty close.
Note: This program uses the Perl 5.10+ say feature, and thus needs to be invoked with the -M5.010 (or -E) command line switch. Per established consensus on meta, such switches used to enable modern language features do not count as extra characters. The shortest solution I can find without say is 83 bytes:
$_=q{use
Term'ReadKey;ReadMode
4;ReadKey,print
for
split/^/,
"\$_=q{$_};eval"};eval
Both of these can also be made more terminal-friendly by (joining the last two lines and) inserting:
;ReadMode
0
before the last }.