Thread: Buffered I/O subsystem

Code:

static char stdout_buf[N];
static char stderr_buf[N];

int main ( void )
{
  ...

  /* Before doing anything else with stdout and stderr */
  setvbuf ( stdout, stdout_buf, _IOFBF, N );
  setvbuf ( seterr, stderr_buf, _IOFBF, N );

  ...
}

The mode options are:

_IOFBF - Full buffering
_IOLBF - Line buffering
_IONBF - unbuffered

I think you can figure out the others, if not, check you reference manual. setvbuf is in stdio.h.

Well you can use the setvbuf() call to change the buffering of a stream.

But I'd leave stderr alone. It's unbuffered by default, so that error messages are not lost in a buffer if the program crashes between reporting the error and finally printing the error.