[lug] Is there a way to get output once it's been redirected to /dev/null?

Zan Lynx zlynx at acm.org
Fri Jun 25 16:58:17 MDT 2010

On 6/25/10 4:35 PM, Jonathan Corbet wrote:
> On Fri, 25 Jun 2010 16:30:27 -0600
> Jeffrey Haemer<jeffrey.haemer at gmail.com>  wrote:
>> Great idea, but I'm missing something.
>> Here's the source for a sample program:
>> #include<stdio.h>
>> int main(void) {
>>    while (1) {
>>      printf("hello, world\n");
>>      sleep(1);
>>    }
>> }
> Either wait longer or put in an fflush(stdout); call.  My guess is that
> stdio is buffering the output into a nice bug chunk.

That is what I think too.

The C stdio functions look at the output on startup and if it's a 
terminal they default to line buffered. If it isn't a terminal then it 
is chunk buffered and that is either 4 or 8K, IIRC.

Zan Lynx
zlynx at acm.org

"Knowledge is Power.  Power Corrupts.  Study Hard.  Be Evil."

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