NAME

ftell, ftello - return a file offset in a stream

SYNOPSIS

#include <stdio.h>
long ftell(FILE *stream);

off_t ftello(FILE *stream);

DESCRIPTION

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 ftell() except for the return type.

Normally the value returned is measured in bytes. However, when stream has been created with open_wmemstream(3C) then the offset of the stream is measured in wide characters. This behavior is consistent with how fseek(3C) and fseeko(3C) treat the offset into the stream.

RETURN VALUES

Upon successful completion, the ftell() and ftello() functions return the current value of the file-position indicator for the stream measured in bytes from the beginning of the file, or wide characters for streams created by open_wmemstream(3C). Otherwise, they return −1 and sets errno to indicate the error.

ERRORS

The ftell() and ftello() functions will fail if:

EBADF

The file descriptor underlying stream is not an open file descriptor.

ESPIPE

The file descriptor underlying stream is associated with a pipe, a FIFO, or a socket.

The ftell() function will fail if:

EOVERFLOW

The current file offset cannot be represented correctly in an object of type long.

The ftello() function will fail if:

EOVERFLOW

The current file offset cannot be represented correctly in an object of type off_t.

USAGE

The ftello() function has a transitional interface for 64-bit file offsets. See lf64(7).

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Standard
MT-Level	MT-Safe