#include "f2c.h"
#include "fio.h"
#ifdef KR_headers
integer f_rew(a) alist *a;
#else
integer f_rew(alist *a)
#endif
{
  unit *b;
  if(a->aunit >= MXUNIT || a->aunit < 0)
    err(a->aerr, 101, "rewind");
  b = &f__units[a->aunit];
  if(b->ufd == NULL || b->uwrt == 3)
    return(0);
  if(!b->useek)
    err(a->aerr, 106, "rewind")
    if(b->uwrt)
    {
      (void) t_runc(a);
      b->uwrt = 3;
    }
  rewind(b->ufd);
  b->uend = 0;
  return(0);
}
