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fseeko
<html> <head> <title>fseeko</title> <META NAME="KEYWORDS" CONTENT="fseeko"> </head> <body BGCOLOR="#ffffff" LINK="#0000ff" VLINK="#0000ff" ALINK="#0000ff" TEXT="#000000"> <center> <h1><b>fseeko</b></h1></center> <PRE> <STRONG><A HREF="/man3/FSEEKO">FSEEKO(3)</A></STRONG> Linux Programmer's Manual <STRONG><A HREF="/man3/FSEEKO">FSEEKO(3)</A></STRONG> 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); Feature Test Macro Requirements for glibc (see <STRONG><A HREF="/man7/feature_test_macros">feature_test_macros(7)</A></STRONG>): 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 <STRONG><A HREF="/man3/fseek">fseek(3)</A></STRONG> and <STRONG><A HREF="/man3/ftell">ftell(3)</A></STRONG> (see <STRONG><A HREF="/man3/fseek">fseek(3)</A></STRONG>), 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 defin- ing _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 in- dicate the error. ERRORS See the ERRORS in <STRONG><A HREF="/man3/fseek">fseek(3)</A></STRONG>. VERSIONS These functions are available under glibc since version 2.1. ATTRIBUTES For an explanation of the terms used in this section, see at- <STRONG><A HREF="/man7/tributes">tributes(7)</A></STRONG>. +-------------------+---------------+---------+ |Interface | Attribute | Value | +-------------------+---------------+---------+ |fseeko(), ftello() | Thread safety | MT-Safe | +-------------------+---------------+---------+ CONFORMING TO POSIX.1-2001, POSIX.1-2008, SUSv2. SEE ALSO <STRONG><A HREF="/man3/fseek">fseek(3)</A></STRONG> COLOPHON This page is part of release 5.05 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/. 2017-09-15 <STRONG><A HREF="/man3/FSEEKO">FSEEKO(3)</A></STRONG></PRE> <center> <h6>Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2025 <a href="http://www.he.net">Hurricane Electric</a>. All Rights Reserved.</h6></center> </body> </html>