fsetpos64
—restore position of a large stream or file ¶Synopsis
#include <stdio.h> int fsetpos64(FILE *fp, const _fpos64_t *pos); int _fsetpos64_r(struct _reent *ptr, FILE *fp, const _fpos64_t *pos);
Description
Objects of type FILE
can have a “position” that records how much
of the file your program has already read. Many of the stdio
functions
depend on this position, and many change it as a side effect.
You can use fsetpos64
to return the large file identified by fp to a
previous position *pos
(after first recording it with fgetpos64
).
See fseeko64
for a similar facility.
Returns
fgetpos64
returns 0
when successful. If fgetpos64
fails, the
result is 1
. The reason for failure is indicated in errno
:
either ESPIPE
(the stream identified by fp doesn’t support
64-bit repositioning) or EINVAL
(invalid file position).
Portability
fsetpos64
is a glibc extension.
Supporting OS subroutines required: close
, fstat
, isatty
,
lseek64
, read
, sbrk
, write
.