Hello world! with limited character repetition

Question

In a language of your choice, write a program that exactly outputs the characters Hello world! followed by a newline. The code:

• should not use any character more than twice (alphanumeric, symbol, whitespace...anything)
• should not use any external resources
• should not use any user input
• should not output anything else

An example of a valid python program:

print("He%so world!"%(2*'l'))

An example of an invalid python program (the character 'r' is used three times):

print("Hel"+chr(108)+'o world!')

Winner is whoever has the most votes after 14 days.

EDIT: A winner has been chosen! Thanks all for your work on this question!

Answer 1

AWK,34

BEGIN{printf"Hel%co world!\n",108}

Answer 2

nginx.conf

set $i l;
return 202 "Hel${i}o world!\n";

In action:

opti# curl -6v "http://localhost/"
* About to connect() to localhost port 80 (#0)
*   Trying ::1...
* connected
* Connected to localhost (::1) port 80 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.26.0
> Host: localhost
> Accept: */*
>
< HTTP/1.1 202 Accepted
< Server: nginx/1.4.1
< Date: Fri, 17 Jan 2014 18:02:08 GMT
< Content-Type: application/octet-stream
< Content-Length: 13
< Connection: keep-alive
<
Hello world!
* Connection #0 to host localhost left intact
* Closing connection #0

Answer 3

HTML — 17 characters

Hello world!

In action:

%echo -n "Hello world!" | wc
       0       2      17
%echo -n "Hello world!" | lynx -dump -stdin

   Hello world!

%

Answer 4

Fugue

From the esolang wiki:

And you can listen to the source code.

Answer 5

Clojure (35)

(printf "He%c%co world!\n",108,108)

The whitespace almost got me, but Clojure allows the use of commas to separate parameters.

Answer 6

Perl, 28 chars

printf"He%so world!\n",'l'x2

Rules tested with:

perl -e '$"="\n";@a=split//,<>;print"@a";' | sort | uniq -c | sort

Answer 7

C (32 characters)

main(){puts("He\x6clo world!");}

Answer 8

Plain TeX - 18 chars

He^^,lo world!\bye

Remark: TeX terminates the paragraph before shipping it, so the "newline" is actually included.

Answer 9

Taking it directly from the instructions on this page:

curl -sL bit.do/gBfx|perl -E'@Q=map{m%OUtPUTS The chARAC.ERS\N*?>([^<]+)%i?$1:()}<>;say$Q[1]'

or, if you wanna be strict with the white-spaces:

PERL

`curl -sL v.gd/92XIMS`=~m%ThE\WChAracTERS.*?>\K[^<]+%i;say$&

or

`curl -sL v.gd/qmwAMh`=~m%outpUtS\WTHE\WChAracTERS.*?>([^<]+)%i;say$1

Advantage: will work for every sentence, but please don't change wording of the question :)

Rules: we can consider this question being an "internal" resource. Without this question, no one would solve it. Should it be me or the program reading it? :)

Backstage story: I almost teared out all my hair trying to debug this! :)

First solution

• using wget -O- leads to 3x -
• sed needed too many /
• so I need curl and perl, but all perl loops like until, while contain 3rd l!
• I needed to replace the loop, this is quite complicated but
  • it seems $1 only works after positive (=~) not negative (!~) match
  • I couldn't use !(..) - too many parentheses :x
  • neither I could use || (I need a pipe!) or or (perl, curl ...)

Second solution

• I reread the rules. White-spaces shouldn't be repeated either - oh my!
• At least could recycle the do{}while idea. Better said, it was forced, the map solution could not be used for using () 2 times, 3rd needed to call open since no more whitespaces are left.
• Find proper url shortener was a story, using goo.gl, bit.ly, is.gd or ow.ly was obviously impossible for the first solution, as was bit.do and dft.ba for the second. Then, url-shorten the URL until you get something you can use, especially with bit.ly and v.gd. Why on earth they use so much lowercase characters?

The regex could be shortened, but I like the instructions to be as long as possible :-)

These rules are damn crazy :)

---

_{PERL v5.10 say feature has to be enabled, e.g. by running PERL -E option}

Answer 10

Keg, 13 bytes

The winner was chosen, but I still want to do it. :) (Astonishingly it is shorter than HTML!)

Hel:o world\!

This is a popularity contest, but the program is very easy to understand despite of the conciseness.

Explanation

Hel          #Push "Hel" onto the stack
   :         #Duplicate the top of the stack (l)
    o world  #Push "o world" onto the stack
           \!#Escape ! and push it onto the stack(since it is an instruction)

Answer 11

LINQPad, C# Expression - 22 chars

"Hello w\x6fr\x006cd!"

Answer 12

PHP, 30 characters

Highly inspired by Vereos's answer.

<?=Hello.' wor'.chr(108),"d!";

Answer 13

HTML - (16 Chars):

Hello Wor&#108d!

Proper HTML would be to put a ; after &#108 but it still compiles fine. :)

Answer 14

C

q=7103816;
main(){printf("%slo world!%c",&q,2+8);}

Works on little-endian platforms, where 7103816 is encoded the same as Hel\0.

Answer 15

Lua - 22 characters

print"Hel\108o World!"

Simple enough, example output

lua -e 'print"Hel\108o World!"'
Hello World!

Answer 16

Яussian

Хелло мир!

A mix of transliteration and proper language :) Google translate will turn it into proper "Hello world!"

Answer 17

C, 41

main(){printf("He%clo world!%c",108,10);}

Answer 18

Javascript, 19ch

> 'Hello Wor\154d!\n'

Character count:

> "'Hello Wor\154d!\n'".length -> 15 //cough, cheating

> "'Hello Wor\\154d!\\n'".length -> 19

With your choice of return, alert(), or nothing? Man, javascript has too many contexts.

Slightly more interesting: ["He",,'o World\n'].join('l')

Answer 19

R

Not gonna win anything, but I didn't see R yet...

'He\154\154o, World!'
'Hello, Wor\154d!'

Answer 20

TI-BASIC, 33 bytes on-calculator

"l→Str1:Disp "He..o World!
Str1:Output(2,3,Ans+Ans

Since TI-BASIC uses tokens instead of characters, I limited myself by token. Make sure the screen is cleared before running the program. Note that l and o are two-byte tokens, but w is a sequence variable and d, e, and r are statistics variables, which are all one-byte tokens. This program first Displays the string without the first two l's, and then uses a different command to paste in the other two. Also note that TI-BASIC has no equivalent to a newline, but when the program ends the cursor does move down to allow further input to the calculator.

Answer 21

Hexish    

0B

Answer 22

Haskell, 27

main=print"Hello Wor\108d!"

Twice-check:

import Data.List
main=getContents>>=print.all((<3).length).group.sort

Answer 23

q/kdb [16 chars]

"hel\154o world"

Answer 24

Node.js - 54 Unicode characters

eval([]+Buffer('consolť.ŬůgĨĢHťŬɬů wɯrɬd!Ģĩ',"ascii"))

console.log outputs a given string and a line shift, unfortunately that initially leaves me with way too many ls and os, so it took some work.

The code creates a buffer from a string and is told to use ascii encoding, this effectively takes all character values mod 256 and stores them in the buffer, the buffer is then added to an empty array, which cause both buffer and array to be converted to string before the addition, an empty array converts to an empty string, and the buffer is implicitly converted using UTF-8 encoding. The result is evaled to produce the desired result.

Answer 25

PHP 5.1.2+

<?="\x48".hasH_file(@cRC32b,__FILE__,'« Tý'|5)." wor\X6Cd!";

The code hashes itself to get the remaining characters. Repeats the characters ".\,'_

A tab messes up the formatting. Base64:

PD89Ilx4NDgiLmhhc0hfZmlsZShAY1JDMzJiLF9fRklMRV9fLCfCqwlUw70nfDUpLiIgd29yXFg2Q2QhIjs=

Answer 26

newLISP

Such a cruel challenge for a Lisp-like language, where so much is possible if only you don't count parentheses... :) But a solution can be found:

 (eval-string(encrypt {`4?3%;=6^9z*9&^m=>*],c;W}{HDMZKOQX~B2OUJ1MJQX1HBF~KU2FZD}))

(81 characters)

which uses the simple encrypt function to pass a command through to the evaluator. The actual command is (println {Hello world!}). (Having "z" and "Z" and "Z" is allowed, according to the comments...:)).

Answer 27

POSIX shell (Bash et al) - 26 chars

printf 'Hel\x6Co world!\n'

Answer 28

k/q (25 chars)

[email protected]"Hello wor%6cd!";

works in either k or q

(btw, the validity can be checked elegantly with |/#:'="[email protected]\"Hello wor%6cd!\";")

Answer 29

http://esolangs.org/wiki/Hello%2B%2B

H

1 letter is all it takes to print that

Answer 30

BASH

printf "a\107Vs\x62G8gd29ybGQhCg=="|base64 -d