Hello world! with limited character repetition
Ruby (1.9+)

Since this is a popularity contest let's try to not use ANY of the characters from 'Hello world!' while still using other characters only a maximum of two times:

puts("S\107VsbG8gV29ybGQhCg".unpack(?m))


It's 40 chars btw.

Bash

And this one uses unicode magic.

Notes:


While the orignal characters appear elsewhere (unlike the ruby example), the printed string contains only non-ascii characters.
Two from the three spaces are actually tabs, so there are no utf-8 characters that appear more than 2 times
As binary some of the octets do appear more than 2 times, hopefully that's not against the rules. I'm trying to resolve them though.


Code:

echo ' ¡'|iconv -t  asCIi//TRANSLIT


For those who don't have a proper font installed it looks like this:



Here is the hexdump:

00000000  65 63 68 6f 20 27 f0 9d  93 97 f0 9d 90 9e f0 9d  |echo '..........|
00000010  91 99 f0 9d 92 8d f0 9d  93 b8 e2 80 8a f0 9d 93  |................|
00000020  a6 f0 9d 97 88 f0 9d 96  97 f0 9d 96 91 f0 9d 98  |................|
00000030  a5 c2 a1 27 7c 69 63 6f  6e 76 09 2d 74 09 61 73  |...'|iconv.-t.as|
00000040  43 49 69 2f 2f 54 52 41  4e 53 4c 49 54 0a        |CIi//TRANSLIT.|
0000004e


You have to run it on a machine where the default charset is utf-8. I tried on an OSX10.8 using iTerm2 with the following environment:



PHP 5.4

This uses zLib: (unfortunately it does uses the characters e and o)

&lt;?=gzuncompress('x▒▒H▒▒▒W(▒/▒IQ▒!qh');


Hexdump:

00000000  3c 3f 3d 67 7a 75 6e 63  6f 6d 70 72 65 73 73 28  |&lt;?=gzuncompress(|
00000010  27 78 9c f3 48 cd c9 c9  57 28 cf 2f ca 49 51 e4  |'x..H...W(./.IQ.|
00000020  02 00 21 71 04 68 27 29  3b                       |..!q.h');|
00000029


+1

Here is the ruby 2.0 code I used to test for duplicates:

d=ARGF.read
p [d.split(//),d.unpack('C*')].map{|x|x.inject(Hash.new(0)){|i,s|i[s]+=1;i}.select{|k,v|v&gt;2}}