Shortest code to produce infinite output

Question

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:

• The comma is both code and data
• Infinite errors (that counts)
• Infinite warnings (that also counts)
• What's Marbelous?

Leaderboard

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>

Answer 1

PowerShell, 8 bytes

for(){1}

Try it online!

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

Answer 2

Dis, 1 byte.

{

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

Answer 3

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.

---

Original answer:

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

Fills the Serial monitor with 0s.

Answer 4

Nim, 16 bytes

while 1>0:echo 0

Answer 5

ℒight, 0 bytes

Prints "#" infinitely.

Answer 6

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.

Answer 7

Seed, 4 bytes

1 87

Try it online!

Answer 8

Dyalog APL: 8 characters

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

{⍞←⍵⋄∇⍵}

Answer 9

Retina, 4 bytes

+:`0

Try it online

Doesn't match, so output 0, then it does match so output 1, now it doesn't so output 0, etc...

Answer 10

Oration, 21 bytes

to iterate, 1
listen,

40 bytes:

to iterate, 1
listen,
capture,
that's it

The first does print() (but it's python 2, so prints infinite ()), the second does print('') (the capture begins a string and the that's it ends it).

Answer 11

Sesos, 2 bytes

0000000: 2c06                                              ,.

Prints an infinite amount of ones.

Try it online! Check Debug to see the generated binary code.

How it works

The binary file above has been generated by assembling the following SASM code.

set numout ; Switch to numeric output

add 1      ; Set the current cell to 1.
jmp        ; Jump to the corresponding exit marker.
    put    ; Print the integer in the current cell to STDOUT.
           ; (implicit jnz)
           ;     If the integer in the current cell is non-zero,
           ;     jump to the previous instruction.

Answer 12

Assembly (MIPS, SPIM), 8 bytes

main:j$0

Try it online!

This has both infinite stdout output and infinite stderr output, meaning that I have \$\infty * 2\$ output. Clearly that makes my answer twice as good as the others and I should win 😏.

Jumps to the zero register, which is an invalid address. Without macros:

main:
    # Jump to the address in the zero register, which is 0
    jr  $zero

This causes the default exception handler to emit the following error message repeatedly while it advances the PC past the offending instruction to "solve" the problem.

  Exception 6  [Bad instruction address]  occurred and ignored
  Exception 6  [Bad instruction address]  occurred and ignored
  Exception 6  [Bad instruction address]  occurred and ignored
...

All while the interpreter also prints this error message to stderr:

Exception occurred at PC=0x00000000
  Bad address in text read: 0x00000000
Exception occurred at PC=0x00000004
  Bad address in text read: 0x00000004
Exception occurred at PC=0x00000008
  Bad address in text read: 0x00000008
...

This continues until it eventually wraps to __start, jumps to main, then jumps back to 0x00000000.

Answer 13

C#, 60

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

Answer 14

Golf-Basic 84, 2 characters

p`

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

Answer 15

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

Answer 16

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}

Answer 17

~-~! - 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.

Answer 18

J 11

echo@-^:_]1

Outputs 0's because inversion (-) does not converge when repeated ad infinitum (^:_).

Answer 19

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.

Answer 20

Coffeescript 15

 alert 0 while 1

Answer 21

Bash - 13

cat /dev/zero

OK, not the shortest, but I'm surprised this isn't here already.

Answer 22

Bash - 7 Characters

echo
$0

Prints endless newlines, at least until your computer crashes.

Answer 23

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.

Answer 24

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.

Answer 25

LOOP, 1

.

Outputs 000000000...

Answer 26

This Programming Language, 2

In the spirit of the Befunge answer,

i'

Outputs 105 indefinitely.

Answer 27

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.

Answer 28

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].

Answer 29

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.

Answer 30

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 ].