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

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Answer 1

Pyth - 2 bytes

#0

Exlanation:

#0
#  Loop forever
 0 Print 0

Answer 2

Flipbit, 4 bytes

^[.]

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Yay for Bra*nfuck derivatives!

Answer 3

Dreaderef, 9 8 7 bytes

5?1 1-1

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Explanation:

In a more readable form (which can still be fed into the preprocessor), this program is:

numo 0
deref 1 -1

The numo (numeric output) statement does just about what you'd expect: it outputs 0. I could have used chro, but that makes it output unprintables and doesn't affect the byte count.

To understand the second line, you have to know a little bit about Dreaderef:

• Programs are loaded into the data space at the beginning of execution.
• The pointer to the current instruction is located at position -1.

What deref 1 -1 does is:

• Dereferences 1 (takes the value of the cell at index 1). This always returns 0.
• Stores the result in cell -1, which is effectively a GOTO to instruction 0.

Dreaderef doesn't have a "load constant" instruction, so the best way to load a constant into a cell is to use some sort of arithmetic instruction or copy it from some other cell with deref, which is what I do here.

Answer 4

Forth, 24 bytes

Defines then calls a word that loops forever, pushing and printing <0> each iteration.

: f begin .s 0 until ; f

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With a do-loop (25 bytes):

: f 0 0 do 0 .s +loop ; f

Prints <1> 0 forever.

Answer 5

PHP, 14 bytes

for(;;)echo 0;

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Answer 6

TIS -n 1 1, 12 bytes

@0
MOV 0 ANY

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Just shoves a bunch of 0\n to the output. On TIO, reached the 128KiB cutoff quite quickly. Without the -n flag, prints null bytes instead.

If you are familiar with TIS-100, you will be used to a 3x4 array of computational nodes, however, this solutions only uses one such node, nominally giving the zeroes downward as output.

The only instruction that send data out of a computational node is MOV, and that requires a source and a destination. the smallest possible source is a single digit number, and the smallest possible destination is UP. However, to produce actual output, the data needs to travel downwards, restricting the choice to either DOWN or ANY.

Answer 7

Gol><>, 1 byte

D

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D is a command designed for debugging, which prints the entire stack (from bottom to top) between brackets. D on empty stack generates []\n to stdout, and the IP loops through the row endlessly.

Alternative solution, 1 byte

Credits to Jo King

N

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Unlike ><>, Gol><> has infinite zeroes at the bottom of the stack, which allows to print the top without pushing anything. Any of Nno will do; N prints 0\n, n prints 0, and o prints null bytes.

Alternatively, there are many 2-byte solutions:

• One of 0-9a-f, l, or m followed by one of NnoD; Try it online!
  • Any of 0-9a-f pushes a hexadecimal digit to the stack, l pushes the current stack size, and m pushes -1.
  • N prints the top as number with newline, n is the same without newline, and o prints as a char.
• S"; Try it online!
  • Initially S" is interpreted as one command which prints the encountered chars up to ending ". The next loop of S" is interpreted as a literal S and then closing ", which prints a single S to stdout.
• " followed by any of NnoD; Try it online!
  • Use " as both opening and closing quote, then print the char.

Answer 8

Ahead, 1 byte

O

Prints 0 forever. O pops the stack and prints that value as a number written out (as opposed to a Unicode character). Like Befunge, the empty stack pops 0, so this will print 0.

Since this is a 1x1 board, the head has nowhere to go and will stay on this cell forever, outputting forever.

Answer 9

Prolog (14 bytes)

a:-write(0),a.

Simple tail recursive predicate in swi-prolog. Called like so a.

Answer 10

Flobnar, 4 bytes

0,_@

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Outputs 0x00 bytes indefinitely.

This works because _ is said to get the conditional from the cell on the other side of it, and then use its value to choose between the east and west cells. It is expected to be evaluated from a vertical direction, but it doesn't have to be.

@ indicates the starting point for the program and evaluates to the return value of the cell to its west (_). _ evaluates what's on the other side (0,) to print 0. , always has a return value of 0, however, and this causes the horizontal if to choose the branch to its east. This is @, which evaluates the cell to its west, continuing the cycle.

Flobnar doesn't have decimal output by default, but the linked implementation has a -d flag which enables . for decimal output. This allows a slightly prettier version that outputs printable characters instead.

0._@

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Answer 11

√ å ı ¥ ® Ï Ø ¿ , 3 bytes

(o)

Will output:

===== OUTPUT =====

0 0 0 0 0 etc.

==================

followed by execution information.

TIO Compiler. Enter the code as the first input and None as the second.

Answer 12

Taxi, 377 369 bytes

-8 bytes by getting rid of the quotes.

Go to Post Office:w 1 l 1 r 1 l.
[B]
! is waiting at Writer's Depot.
! is waiting at Writer's Depot.
! is waiting at Writer's Depot.
Go to Zoom Zoom:s 1 l 1 l 4 l 2 r.
Go to Writer's Depot:w.
Pickup a passenger going to Post Office.
Pickup a passenger going to Post Office.
Pickup a passenger going to Post Office.
Go to Post Office:n 3 r 2 r 3 r 1 l.
Switch to plan B.

The repetition of the passengers is needed for the driver to get enough fare to get enough gas to continue forever.

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Answer 13

Perl 6, 8 bytes

Thanks to nwellnhof for this solution.

.say xx*

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Prints (Any) infinitely.

Perl 6, 10 bytes

1...!*.say

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Defines a list that increments until the result of printing the current number is false (which never happens).

Answer 14

Aheui (esotope), 6 bytes

박망

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---

or simillar codes with same length like following;

반망
받망
...
박맣
...

will produce infinite output.

Answer 15

Clean, 7 bytes

f=[0:f]

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Gives [0,0,0,0,...

Answer 16

Gol><>, 1 byte

n

There we go, I feel like this cheats a little bit, but it works! Now to golf this more... ;)

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Answer 17

Muriel, 39 bytes

A:"\";.A;@\"A:\\\"\"+|A+A";@"A:\""+|A+A

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This is near identical to the Muriel quine, except I've changed the print command in the last instruction to an eval command, and the addition of .A; in order to print something (in this case, the shortest thing was a part of the source code ("+|A+A";@"A:\""+|A+A) itself).

Answer 18

05AB1E, 2 bytes

Version 1 (3 bytes)

[A,

prints out the alphabet

Version 1 (2 bytes)

[,

Outputs infinite newlines

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Answer 19

Voovoos, 3 bytes

x.<

Pretty much just endlessly bounces between the . and <
. pops the top of the stack and prints it, but if you pop an empty stack in voovoos you get 0, so it just endlessly prints 0.

Answer 20

YABALL, 3 bytes

!.?

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Explanation

!                  Go off of "reverse mode" (a mode where the IP goes left instead of right) if in reverse mode, otherwise no-op
.                  Print current cell, which is NUL
?                  Go in "reverse mode"

Basically an infinite loop printing NULs.

The commands are executed like so: !.?.!.?.!.? ...

Answer 21

MINOL, 5 bytes

GOTO0

Any expression in MINOL that isn't entered as part of a program (that is, isn't assigned a line number by the user) is considered line 0. While seemingly not a part of the official spec (which, as far as I can tell, is a series of letters sent to and subsequently reformatted and published by 'Dr. Dobb's Journal of Computer Calisthenics and Orthodontia' in 1976), lines executed this way always seem to spit out a newline. This obviously wouldn't be the case in a full program, which would take 11 bytes (inc. the trailing CR):

1 PR:GOTO1

Answer 22

Turing Machine But Way Worse, 27 13 bytes

0 0 0 1 0 1 0

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Outputs infinite NUL characters.

Answer 23

Triangular, 4 bytes

,%0/

Prints 0 repeatedly.

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Ungolfed:

  ,
 % 0
/

Answer 24

Underload, 8 bytes

(:S:^):^

Endlessly outputs :S:^

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Answer 25

Pyth, 3 2 bytes

#d

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Prints the string " " (single space) until a print instruction produces an error (which, I mean, I guess could happen).

Answer 26

PHP, 16 bytes 8 bytes

My first attempt and this Code Golf :)

while(a)

I'm sure I could make it better without that echo? hmm...

Answer 27

33, 5 bytes

1a[o]

Explanation:

1a    (Set the accumulator to 1, to allow the loop to continue to run)
  [o] (Print the accumulator, 1, forever)

Answer 28

bitch, 3 bytes

>/<

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---

Explanation

>      Begin loop
 /     Print accumulator value (intialised to 0)
  <    Loop back to beginning of loop

Answer 29

TSQL, 16 17 bytes

l:PRINT'1'GOTO l

WHILE 1=1PRINT'1'

Answer 30

MarioLANG, 7 bytes

>:<
===

Mario will walk back and forth, printing as he does.

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