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FSEEKO

Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
Index Return to Main Contents
 

NAME

fseeko, ftello - seek to or report file position  

SYNOPSIS

#include <stdio.h>

int fseeko(FILE *stream, off_t offset, int whence);

off_t ftello(FILE *stream);
.fi

Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):

fseeko(),
ftello():

_FILE_OFFSET_BITS == 64 || _POSIX_C_SOURCE >= 200112L
(defining the obsolete _LARGEFILE_SOURCE macro also works)
 

DESCRIPTION

The fseeko() and ftello() functions are identical to fseek(3) and ftell(3) (see fseek(3)), respectively, except that the offset argument of fseeko() and the return value of ftello() is of type off_t instead of long.

On some architectures, both off_t and long are 32-bit types, but defining _FILE_OFFSET_BITS with the value 64 (before including any header files) will turn off_t into a 64-bit type.  

RETURN VALUE

On successful completion, fseeko() returns 0, while ftello() returns the current offset. Otherwise, -1 is returned and errno is set to indicate the error.  

ERRORS

See the ERRORS in fseek(3).  

VERSIONS

These functions are available under glibc since version 2.1.  

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
fseeko(), ftello() Thread safetyMT-Safe

 

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, SUSv2.  

SEE ALSO

fseek(3)  

COLOPHON

This page is part of release 4.13 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
VERSIONS
ATTRIBUTES
CONFORMING TO
SEE ALSO
COLOPHON