Originální popis anglicky:
ftell, ftello - return a file offset in a stream
Návod, kniha: POSIX Programmer's Manual
#include <stdio.h>
long ftell(FILE *
stream);
off_t ftello(FILE *stream);
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.
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.
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.
None.
None.
None.
None.
fgetpos() ,
fopen() ,
fseek() ,
lseek() , the Base
Definitions volume of IEEE Std 1003.1-2001,
<stdio.h>
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
.
