what is this supposed to do?

[Stephen Clamage]

langer at gibbs.uchicago.edu (Steve Langer) writes:

>What is the expected output from the following program? Is it defined?

>#include <stdio.h>
>main() {
>   printf("1 << 32 = %o\n", ((unsigned) 1) << 32);
>}

It is not defined, so the variation in outputs you got is legal.
In 3.3.7, the Standard says "If the value of the right operand
[of the shift operator] ... is greater than or equal to the width in
bits of the promoted left operand, the behavior is undefined."
-- 

Steve Clamage, TauMetric Corp, steve at taumet.com