# Shortest code to produce infinite output

Write the shortest code you can that produces an infinite output.

That's all. You code will only be disqualified if it stops producing output at some point. As always in code golf, the shortest code wins.

Here's a list of answers that I think are really clever, so they can get credit:

var QUESTION_ID=13152,OVERRIDE_USER=8611;function answersUrl(e){return"https://api.stackexchange.com/2.2/questions/"+QUESTION_ID+"/answers?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+ANSWER_FILTER}function commentUrl(e,s){return"https://api.stackexchange.com/2.2/answers/"+s.join(";")+"/comments?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+COMMENT_FILTER}function getAnswers(){jQuery.ajax({url:answersUrl(answer_page++),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){answers.push.apply(answers,e.items),answers_hash=[],answer_ids=[],e.items.forEach(function(e){e.comments=[];var s=+e.share_link.match(/\d+/);answer_ids.push(s),answers_hash[s]=e}),e.has_more||(more_answers=!1),comment_page=1,getComments()}})}function getComments(){jQuery.ajax({url:commentUrl(comment_page++,answer_ids),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){e.items.forEach(function(e){e.owner.user_id===OVERRIDE_USER&&answers_hash[e.post_id].comments.push(e)}),e.has_more?getComments():more_answers?getAnswers():process()}})}function getAuthorName(e){return e.owner.display_name}function process(){var e=[];answers.forEach(function(s){var r=s.body;s.comments.forEach(function(e){OVERRIDE_REG.test(e.body)&&(r="<h1>"+e.body.replace(OVERRIDE_REG,"")+"</h1>")});var a=r.match(SCORE_REG);a&&e.push({user:getAuthorName(s),size:+a[2],language:a[1],link:s.share_link})}),e.sort(function(e,s){var r=e.size,a=s.size;return r-a});var s={},r=1,a=null,n=1;e.forEach(function(e){e.size!=a&&(n=r),a=e.size,++r;var t=jQuery("#answer-template").html();t=t.replace("{{PLACE}}",n+".").replace("{{NAME}}",e.user).replace("{{LANGUAGE}}",e.language).replace("{{SIZE}}",e.size).replace("{{LINK}}",e.link),t=jQuery(t),jQuery("#answers").append(t);var o=e.language;/<a/.test(o)&&(o=jQuery(o).text()),s[o]=s[o]||{lang:e.language,user:e.user,size:e.size,link:e.link}});var t=[];for(var o in s)s.hasOwnProperty(o)&&t.push(s[o]);t.sort(function(e,s){return e.lang>s.lang?1:e.lang<s.lang?-1:0});for(var c=0;c<t.length;++c){var i=jQuery("#language-template").html(),o=t[c];i=i.replace("{{LANGUAGE}}",o.lang).replace("{{NAME}}",o.user).replace("{{SIZE}}",o.size).replace("{{LINK}}",o.link),i=jQuery(i),jQuery("#languages").append(i)}}var ANSWER_FILTER="!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe",COMMENT_FILTER="!)Q2B_A2kjfAiU78X(md6BoYk",answers=[],answers_hash,answer_ids,answer_page=1,more_answers=!0,comment_page;getAnswers();var SCORE_REG=/<h\d>\s*([^\n,]*[^\s,]),.*?(\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/,OVERRIDE_REG=/^Override\s*header:\s*/i;
body{text-align:left!important}#answer-list,#language-list{padding:10px;width:290px;float:left}table thead{font-weight:700}table td{padding:5px}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/codegolf/all.css?v=83c949450c8b"> <div id="answer-list"> <h2>Leaderboard</h2> <table class="answer-list"> <thead> <tr><td></td><td>Author</td><td>Language</td><td>Size</td></tr></thead> <tbody id="answers"> </tbody> </table> </div><div id="language-list"> <h2>Winners by Language</h2> <table class="language-list"> <thead> <tr><td>Language</td><td>User</td><td>Score</td></tr></thead> <tbody id="languages"> </tbody> </table> </div><table style="display: none"> <tbody id="answer-template"> <tr><td>{{PLACE}}</td><td>{{NAME}}</td><td>{{LANGUAGE}}</td><td>{{SIZE}}</td><td><a href="{{LINK}}">Link</a></td></tr></tbody> </table> <table style="display: none"> <tbody id="language-template"> <tr><td>{{LANGUAGE}}</td><td>{{NAME}}</td><td>{{SIZE}}</td><td><a href="{{LINK}}">Link</a></td></tr></tbody> </table>

• All answers disqualified because at some point the Earth will be swallowed by the sun, and at some point the universe will die :P Nov 9, 2013 at 20:00
• Does "infinite until your computer crashes" count? <_< Nov 10, 2013 at 1:39
• If I write mine in Piet, can I count the pixels of the text the other programs used? I believe the smallest possible repeating Piet program would be 6 pixels. That beats Befunge if "off" pixels still count. Nov 12, 2013 at 20:27
• @Izkata So any answer that crashes your computer is also allowed :D Jul 11, 2014 at 20:11
• @Doorknob So really, the challenge is to produce infinite output in a finite amount of time. Sounds easy enough. Apr 10, 2015 at 21:15

# Zsh, 15 bytes

while;do 0;done


prints command not found: 0 infinitely

Try it online!

# PowerShell, 8 bytes

for(){1}


Try it online!

Not the most clever, but it gets the job done.

# Dis, 1 byte.

{


Outputs infinite amount of NULL characters; may be slow, depending on the implementation.

## Arduino, 61 60 bytes

Managed to shave off one byte by changing what counts as "output".

void setup(){pinMode(13,1);digitalWrite(13,1);}void loop(){}


Explanation:

void setup() {
pinMode(13, OUTPUT); // OUTPUT is defined as 1
// Arduino boards have a built-in LED connected to pin 13, hence the choice of pin
digitalWrite(13, HIGH); // HIGH is defined as 1
}

void loop() {}


This leaves the built-in LED on, which in a sense is output.

void setup(){Serial.begin(300);}void loop(){Serial.print(0);}


Fills the Serial monitor with 0s.

# Nim, 16 bytes

while 1>0:echo 0


# ℒight, 0 bytes

Prints "#" infinitely.

# TRANSCRIPT, 33 bytes

You can see a f here.
>TIE F TO F


Try it online!

Generate endless warnings due to unclosed loop. At first it doesn't seem possible to loop infinitely in TRANSCRIPT because it only have for loops, but this works.

# Seed, 4 bytes

1 87


Try it online!

• Welcome to Code Golf, and nice answer! Feb 17 at 3:34

# Dyalog APL: 8 characters

Now you can choose what to infinitely print out! Yeeeay!!!

{⍞←⍵⋄∇⍵}


# C#, 60

class A{static void Main(){for(;;System.Console.Write(1));}}


## Golf-Basic 84, 2 characters

p


Causes upper-right line of 5 pixels to alternate continuously.

## Assembly X86 - 44

Ok Im not a geek with assembly x86 but I wanted just to add this as a possible solution. COnsidering the number of dependencies needed by assembly code this code should be the shortest, a simple infinite loop that prints "x":

loop:
movl $120, %rdi call putchar jmp loop  # awk, 15/19 chars Canonical version, 19 characters: BEGIN{for(;;)print}  Version requiring user input (one newline will do), 14 chars (scores as 15 because of the required input): {for(;;)print}  # ~-~! - 17 bytes, with cheating 14 bytes '=|@*:'&*|:'&|.|:  ~-~! has a very limited set of characters, and does not support explicit numbers, so yeah. Outputs infinite .s. If I sway the rules a bit and have the user input the character to be output infinitely, I can have 15 bytes: '=|@*:'&*|:'&^:  Depending on the implementation, the last : for both of these can be left out, lowering the byte counts to 16 and 14. • Please link to a web page describing this language. Google turns up nothing, because the language name is just punctuation. Mar 10, 2014 at 23:24 • @tbodt It's over here; the language is unimplemented but it wasn't designed for this question and I didn't influence it's development at all. :P Mar 11, 2014 at 8:19 ## J 11 echo@-^:_]1  Outputs 0's because inversion (-) does not converge when repeated ad infinitum (^:_). A couple of attempts for AVR, starting with one of the older MEGA/TINY models: inc r1 out DIRC, r0 out DIRC, r1 rjmp .-2  And for XMEGA: inc r0 sts PORTC_DIR, r0 rjmp .-2  Both of these rely on registers being cleared at reset. The output is toggling the direction of PORTC pin 0 (input/output). You need to connect a pull-up resistor to this pin to create a square wave. # Coffeescript 15  alert 0 while 1  • Or: loop alert() Apr 11, 2015 at 15:57 # Bash - 13 cat /dev/zero  OK, not the shortest, but I'm surprised this isn't here already. • Even shorter: cat /dev/zero. Jun 22, 2014 at 22:05 • Ah, thanks! I knew I was forgetting something :) Jun 22, 2014 at 22:07 # Bash - 7 Characters echo$0


Prints endless newlines, at least until your computer crashes.

## k4/q (11)

{x}{x""}/-1


The second function, {x""}, sends the empty string to x. If x is an integer, it's interpreted as a file descriptor. If x is 1 or 2, this means to print to stdout or stderr. If x is -1 or -2, this means to additionally print a newline. The result of sending a string to a file descriptor is that file descriptor.

The first function {x} is an idempotent function. (k has an actual idempotent function, ::, but in this context, it would have to be written (::), so this is shorter.)

The construct g f/x, where g and f are functions, is a variation on functional "fold": f x is called, then g f x is tested as a boolean; if it is false, execution stops; if not, f is called on the result of the prior call. (The return value is the result of the last call to f.) Every integer but 0 is truthy, so the -1 returned by {x""} -1 allows the execution to continue.

As a bonus, and at no extra character cost, if you swap the / for a \, you'll waste infinite amounts of RAM too: g f\x does the same thing, but it saves all the intermediate results as it runs--its return value is the full list of intermediate returns of f.

Just for fun, here's another alternate version. It's the same length, but only valid in k (not q):

{x}{x@$x}/1  This one prints "1"s forever, through more or less the same method, but a couple details are slightly different. # CJam, 6 bytes 1{1p}h  or {1p1}g  which prints an infinite number of 1\n without risk of stack overflow (as there's no recursion). I think CJam might be younger than the question, but this answer isn't a winner, so I don't see any harm. # LOOP, 1 .  Outputs 000000000... # This Programming Language, 2 In the spirit of the Befunge answer, i'  Outputs 105 indefinitely. # Turing Machine Code (9) (This is the dialect of turing machine code used by many online turing machine simulators) 0 * 1 r *  It will endlessly ouput ones while moving rightward along the tape. # Mathematica, 34 33 bytes $IterationLimit=∞;#0@Print@1&[]


If there were no limitation on the maximum length of evaluation chain in Mathematica, #0@Print@1&[] is only 13 bytes, 4 bytes shorter than For[,0<1,Print@1].

Qt 5.4 QMake pro file, 42 chars

defineReplace(A){log(A)return($$A())}$$A()


Is an infinite loop, but sadly gets caught out by qmake interpreter before it can get very far.

AAAA[...]Ran into infinite recursion (depth > 100).


Not sure if that counts under disqualification.

## Self-modifying Brainfuck, 4 bytes

Prints ] forever. Note that the traditional BF programs work as well.

<[.]


The pointer starts one to the right of the source code on the tape, so moving left once puts the pointer at ].

## Simplefunge, 3 chars

Does it count if, you know, it is your own language?

>o<


Prints 0 over and over again, as the tape is initialized as a tape of infinite zeros.

# PlatyPar, 3 Bytes

1WA


Explanation:

1    ## push 1 to the stack
W   ## while(stack[-1])

,

, outputs its contents, and passes it on to the next cell (,). In the event of not being given input, a 0` will be passed in.