fflush.c raw

   1  #include "stdio_impl.h"
   2  
   3  /* stdout.c will override this if linked */
   4  static FILE *volatile dummy = 0;
   5  weak_alias(dummy, __stdout_used);
   6  weak_alias(dummy, __stderr_used);
   7  
   8  int fflush(FILE *f)
   9  {
  10  	if (!f) {
  11  		int r = 0;
  12  		if (__stdout_used) r |= fflush(__stdout_used);
  13  		if (__stderr_used) r |= fflush(__stderr_used);
  14  
  15  		for (f=*__ofl_lock(); f; f=f->next) {
  16  			FLOCK(f);
  17  			if (f->wpos != f->wbase) r |= fflush(f);
  18  			FUNLOCK(f);
  19  		}
  20  		__ofl_unlock();
  21  
  22  		return r;
  23  	}
  24  
  25  	FLOCK(f);
  26  
  27  	/* If writing, flush output */
  28  	if (f->wpos != f->wbase) {
  29  		f->write(f, 0, 0);
  30  		if (!f->wpos) {
  31  			FUNLOCK(f);
  32  			return EOF;
  33  		}
  34  	}
  35  
  36  	/* If reading, sync position, per POSIX */
  37  	if (f->rpos != f->rend) f->seek(f, f->rpos-f->rend, SEEK_CUR);
  38  
  39  	/* Clear read and write modes */
  40  	f->wpos = f->wbase = f->wend = 0;
  41  	f->rpos = f->rend = 0;
  42  
  43  	FUNLOCK(f);
  44  	return 0;
  45  }
  46  
  47  weak_alias(fflush, fflush_unlocked);
  48