ftell#
Synopsis#
#include <stdio.h>
long ftell(FILE *stream);
off_t ftello(FILE *stream);
Status#
Partially implemented
Conformance#
IEEE Std 1003.1-2017
Description#
The purpose is to return a file offset in a stream. The ftell()
function shall obtain the current value of the
file-position indicator for the stream pointed to by stream.
The ftell()
function shall not change the setting of errno if successful.
The ftello()
function shall be equivalent to ftell()
, except that the return value is of type off_t
and the
ftello()
function may change the setting of errno
if successful.
Return value#
Upon successful completion, ftell()
and ftello()
shall return the current value of the file-position indicator for
the stream measured in bytes from the beginning of the file.
Otherwise, ftell()
and ftello()
shall return -1
, and set errno
to indicate the error.
Errors#
The ftell()
and ftello()
functions
shall fail if:
EBADF
- The file descriptor underlying stream is not an open file descriptor.EOVERFLOW
- Forftell()
, the current file offset cannot be represented correctly in an object of type long.EOVERFLOW
- Forftello()
, the current file offset cannot be represented correctly in an object of typeoff_t
.ESPIPE
- The file descriptor underlying stream is associated with a pipe, FIFO, or socket.
Tests#
Untested
Known bugs#
None