The
fseek() function sets the file position indicator for the stream pointed to by
stream. The new position, measured in bytes, is obtained by adding
offset bytes to the position specified by
whence. If
whence is set to
SEEK_SET,
SEEK_CUR, or
SEEK_END, the offset is relative to the start of the file, the current position indicator, or end-of-file, respectively. A successful call to the
fseek() function clears the end-of-file indicator for the stream and undoes any effects of the
ungetc(3) function on the same stream.
The
fseeko() function is identical to the
fseek() function except that the
offset argument is of type
off_t.
The
ftell() function obtains the current value of the file position indicator for the stream pointed to by
stream.
The
ftello() function is identical to the
ftell() function except that the return value is of type
off_t.
The
rewind() function sets the file position indicator for the stream pointed to by
stream to the beginning of the file. It is equivalent to:
(void)fseek(stream, 0L, SEEK_SET)
except that the error indicator for the stream is also cleared (see
clearerr(3)).
In this implementation, the
fgetpos() and
fsetpos() functions are alternative interfaces equivalent to
ftell(),
ftello(),
fseek() and
fseeko() (with whence set to
SEEK_SET), setting and storing the current value of the file offset into or from the object referenced by
pos. In others implementations, an “
fpos_t” object may be a complex object and these routines may be the only way to portably reposition a text stream.