[New] ITT We determine if your programs halt

Give us your programs, and we'll tell you if they halt!

Bring em on!

(loop)

start:
  hlt

>>2
 Yes! That does not halt. I can say with 100% confidence.

>>3
 Yes! That also halts.

NEXT!

#include <stdint.h>
#include <stdlib.h>

int main(void)
{ for(uint32_t i = arc4random_uniform(2); i;);
  return 0; }

#!/bin/sh
yes That does not halt.

>>5
This halts eventually, given unlimited execution time.

>>5
 Does not halt. Not hard at all!

>>6
 Does not halt. Could have found this out by reading ``man yes''

NEXT!

>>8 Here
Just clarifying, >>5 does halt sometimes. However, most of the time it will not halt.

Thanks. NEXT!

#!/bin/sh
man yes


pushl $3
pushl $2       
call power       
addl $8, %esp       
pushl %eax                   
pushl $2       
pushl $5           
call power   
addl $8, %esp   
popl %ebx       
addl %eax, %ebx                   
movl $1, %eax       
int $0x80
 .type power, @function
power:
 pushl %ebp       
 movl %esp, %ebp   
 subl $4, %esp       
 movl 8(%ebp), %ebx   
 movl 12(%ebp), %ecx   
 movl %ebx, -4(%ebp)                   
power_loop_start:
 cmpl $1, %ecx   
 je end_power
 movl -4(%ebp), %eax   
 imull %ebx, %eax   
 movl %eax, -4(%ebp)   
 decl %ecx       
 jmp power_loop_start   
end_power:
 movl -4(%ebp), %eax   
 movl %ebp, %esp   
 popl %ebp       
 ret

main = print=<<($[0..])=<<(return.([return.return.head,return.tail]!!)=<<randomRIO(0,1))

>>7-9
wrong. read ISO/IEC 9899:1999 and the arc4random(3) man page.

main = print $ cycle "LO"

What about this

(defun does-this-halt (n x) 
  (labels ((f (n)
             (if (< n 2) t                  
                 (multiple-value-bind (div mod)
                     (truncate n x)                
                   (if (zerop mod)
                       (f div)
                       (f (+ (1- x) (* n (1+ x)))))))))
    (f n)))

(let* ((state (make-random-state))
       (n (random (ash 1 32) state))
       (x (random n state)))
  (does-this-halt n x))

Assume proper TCO is done on does-this-halt.

SET x TO 0;
SET y TO 1;
LABEL l;
IF x THEN GOTO l;
SET x TO 1;
SEND x TO 1~0~{y}=1;

The name of the language is TwoDucks.

SEND x TO MY ANUS

Also, this in FIOC:

def foo():
    foo()

http://www.kernel.org/pub/linux/kernel/v2.6/testing/linux-2.6.35-rc3.tar.bz2

Will it halt?

#!/bin/sh
halt

>>16
If you actually write a program instead of just copying it from the wiki, I might consider.

?@#

while (halt());

((call/cc call/cc) (call/cc call/cc))

while (1) { fork() };

>>23
huh, I thought the fixed point of call/cc was call/cc. So I'd have expected this to return a function equivalent to call/cc

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main()
{
   srand(time(NULL));
   float a, b, c, d;
   while(true)
   {
      a = (float)rand();
      b = (float)rand();
      c = (float)rand();
      d = (float)rand();
      if((a/b) == (c/d))
      {
         break;
      }
   }
   printf("Halt!")
   return 0;
}
Actually, I don't think this will work ...

>>26
This will probably eventually halt, but I'm curious if there are any cases where it won't halt. It depends on rand's implementation.

Hey! What about >>21?

Guise, stop posting programs that invoke external functionality, it is impossible to evaluate if they will halt or not without looking up the external code which might very well be proprietary or out of reach.

>>29
Good point, RMS

>>20
look again, that program isn't on the wiki.

int main(int argc, char *argv[]) {
    while (0 == 1 == 0) ;
}

>>32
No.  Assembles to
40047f:       eb fe                   jmp    40047f <main+0xb>

current status of this thread:
programs posted: >>2,3,5,6,10-14,16-19,21-24,26,32 (19)
correctly answered (1 point each): >>2,3,6,26,32 (5)
incorrectly answered (-1 point each): >>5 (1)
not answered: >>10-14,16-19,21-24 (13)

your score: 4/19 (about 21%).

#include <stdlib.h>
#include <time.h>

int main(void) {
    int i;

    srand(time(NULL));
    i = rand() % 2;

    if(i) for(;;);
    return 0;
}

>>35 here.
I'd like the answer to be either "halts" or "doesn't halt".
No shit like probability.

>>35
Not enough information. We need to know the time upon execution.

>>36
If you consider the program's input the current time, it will halt in certain cases and not halt in the rest. It's no different from any range of functions depending on user input. Will halt for certain inputs and won't halt for other inputs. The actual values for which it would halt and which it wouldn't halt can be determined exactly if the rand implementation internals is known (depends on libc's code).

>>36
It does both depending on what time it was run.

@echo off
rem Double Dice
title Double Dice!
:S
echo Double Dice!
set money=100
echo.
:1
echo How much do you wager?
set /p wager=You have $%money%:
if /I %wager%==save goto :Score

if /I %wager%==help goto :Help
if /I %wager%==delete goto :Del
if /I %wager%==clear goto :Cls
if %wager% LSS 0 echo You can't wager a negative! &goto :1
if %wager% GTR %money% echo You don't have that money! &goto :1
set /a money="money-wager"
set /a DICE1=%random% %%6 + 1 >nul
echo You rolled a %DICE1%.
set /a DICE2=%random% %%6 + 1 >nul
echo You rolled a %DICE2%
if %DICE1%==%DICE2% goto :WIN!
echo.
if %money%==0 goto :F
goto :1
:F
echo Do you want to play again?(y/n)
set /p input=(y/n):
if /I %input%==y Cls &goto :S
if /I %input%==n goto :GO
goto :F
:WIN!
echo.
echo You Win! Here's your winnings!
echo.
set mem=%wager%
set /a wager="wager*6+wager"
set /a money="money+wager"
set /a wager="wager-mem"
echo You've won $%wager%!
set wager=0
echo.
goto :1
:GO
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
echo GAME OVER
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
ping 127.0.0.1 -n 1 >nul
echo.
echo.
:Score
set /p name=Type your name here:
echo %Name% : $%Money%>>Highscore.data
exit

:Help
echo.
echo Double Dice is a game of chance. If you get the same number twice,
echo the wager that you bet is returned sixfold. Otherwise you get nothing.
echo There are few commands in this program:
echo Save: This enters your profile into the highscore chart
echo Highscore: This loads the highscore if it is present
echo Delete: Removes the Highscore
echo Clear: Clears the screen
echo Help: Returns this information form.
echo.
goto :1