man-pages/man2/llseek.2.html
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<H1>LLSEEK</H1>
Section: Linux Programmer's Manual (2)<BR>Updated: 2017-09-15<BR><A HREF="#index">Index</A>
<A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR>
<A NAME="lbAB">&nbsp;</A>
<H2>NAME</H2>
_llseek - reposition read/write file offset
<A NAME="lbAC">&nbsp;</A>
<H2>SYNOPSIS</H2>
<PRE>
<B>#include &lt;<A HREF="file:///usr/include/sys/types.h">sys/types.h</A>&gt;</B>
<B>#include &lt;<A HREF="file:///usr/include/unistd.h">unistd.h</A>&gt;</B>
<B>int _llseek(unsigned int </B><I>fd</I><B>, unsigned long </B><I>offset_high</I><B>,</B>
<B> unsigned long </B><I>offset_low</I><B>, loff_t *</B><I>result</I><B>,</B>
<B> unsigned int </B><I>whence</I><B>);</B>
</PRE>
<P>
<I>Note</I>:
There is no glibc wrapper for this system call; see NOTES.
<A NAME="lbAD">&nbsp;</A>
<H2>DESCRIPTION</H2>
The
<B>_llseek</B>()
system call repositions the offset of the open file description associated
with the file descriptor
<I>fd</I>
to
<I>(offset_high&lt;&lt;32) | offset_low</I>
bytes relative to the beginning of the file, the current file offset,
or the end of the file, depending on whether
<I>whence</I>
is
<B>SEEK_SET</B>,
<B>SEEK_CUR</B>,
or
<B>SEEK_END</B>,
respectively.
It returns the resulting file position in the argument
<I>result</I>.
<P>
This system call exists on various 32-bit platforms to support
seeking to large file offsets.
<A NAME="lbAE">&nbsp;</A>
<H2>RETURN VALUE</H2>
Upon successful completion,
<B>_llseek</B>()
returns 0.
Otherwise, a value of -1 is returned and
<I>errno</I>
is set to indicate the error.
<A NAME="lbAF">&nbsp;</A>
<H2>ERRORS</H2>
<DL COMPACT>
<DT id="1"><B>EBADF</B>
<DD>
<I>fd</I>
is not an open file descriptor.
<DT id="2"><B>EFAULT</B>
<DD>
Problem with copying results to user space.
<DT id="3"><B>EINVAL</B>
<DD>
<I>whence</I>
is invalid.
</DL>
<A NAME="lbAG">&nbsp;</A>
<H2>CONFORMING TO</H2>
This function is Linux-specific, and should not be used in programs
intended to be portable.
<A NAME="lbAH">&nbsp;</A>
<H2>NOTES</H2>
Glibc does not provide a wrapper for this system call.
To invoke it directly, use
<B><A HREF="/cgi-bin/man/man2html?2+syscall">syscall</A></B>(2).
However, you probably want to use the
<B><A HREF="/cgi-bin/man/man2html?2+lseek">lseek</A></B>(2)
wrapper function instead.
<A NAME="lbAI">&nbsp;</A>
<H2>SEE ALSO</H2>
<B><A HREF="/cgi-bin/man/man2html?2+lseek">lseek</A></B>(2),
<B><A HREF="/cgi-bin/man/man2html?2+open">open</A></B>(2),
<B><A HREF="/cgi-bin/man/man2html?3+lseek64">lseek64</A></B>(3)
<A NAME="lbAJ">&nbsp;</A>
<H2>COLOPHON</H2>
This page is part of release 5.05 of the Linux
<I>man-pages</I>
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
<A HREF="https://www.kernel.org/doc/man-pages/.">https://www.kernel.org/doc/man-pages/.</A>
<P>
<HR>
<A NAME="index">&nbsp;</A><H2>Index</H2>
<DL>
<DT id="4"><A HREF="#lbAB">NAME</A><DD>
<DT id="5"><A HREF="#lbAC">SYNOPSIS</A><DD>
<DT id="6"><A HREF="#lbAD">DESCRIPTION</A><DD>
<DT id="7"><A HREF="#lbAE">RETURN VALUE</A><DD>
<DT id="8"><A HREF="#lbAF">ERRORS</A><DD>
<DT id="9"><A HREF="#lbAG">CONFORMING TO</A><DD>
<DT id="10"><A HREF="#lbAH">NOTES</A><DD>
<DT id="11"><A HREF="#lbAI">SEE ALSO</A><DD>
<DT id="12"><A HREF="#lbAJ">COLOPHON</A><DD>
</DL>
<HR>
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Time: 00:05:33 GMT, March 31, 2021
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