src/stdio/ftell.c

   1 #include "stdio_impl.h"
   2 #include <limits.h>
   3 #include <errno.h>
   4
   5 off_t __ftello_unlocked(FILE *f)
   6 {
   7         off_t pos = f->seek(f, 0,
   8                 (f->flags & F_APP) && f->wpos > f->wbase
   9                 ? SEEK_END : SEEK_CUR);
  10         if (pos < 0) return pos;
  11
  12         /* Adjust for data in buffer. */
  13         return pos - (f->rend - f->rpos) + (f->wpos - f->wbase);
  14 }
  15
  16 off_t __ftello(FILE *f)
  17 {
  18         off_t pos;
  19         FLOCK(f);
  20         pos = __ftello_unlocked(f);
  21         FUNLOCK(f);
  22         return pos;
  23 }
  24
  25 long ftell(FILE *f)
  26 {
  27         off_t pos = __ftello(f);
  28         if (pos > LONG_MAX) {
  29                 errno = EOVERFLOW;
  30                 return -1;
  31         }
  32         return pos;
  33 }
  34
  35 weak_alias(__ftello, ftello);
  36
  37 LFS64(ftello);