The functionality described on this reference page is aligned with
the ISO C standard. Any conflict between the
requirements described here and the ISO C standard is unintentional.
This volume of IEEE Std 1003.1-2001 defers to
the ISO C standard.
The ftell() function shall obtain the current value of the file-position
indicator for the stream pointed to by
stream.
The
ftello() function shall be equivalent to ftell(), except
that the return value is of type off_t.
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, cast to long and off_t respectively, 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
For ftell(), the current file offset cannot be represented correctly
in an object of type long.
EOVERFLOW
For ftello(), the current file offset cannot be represented
correctly in an object of type off_t.
ESPIPE
The file descriptor underlying stream is associated with a pipe
or FIFO.
The ftell() function may fail if:
ESPIPE
The file descriptor underlying stream is associated with a socket.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
fgetpos() , fopen() , fseek()
, lseek() , the Base Definitions volume of IEEE Std 1003.1-2001,
<stdio.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
