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.TH IF_NAMEINDEX "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.

.SH NAME
if_nameindex
\(em return all network interface names and indexes
.SH SYNOPSIS
.LP
.nf
#include <net/if.h>
.P
struct if_nameindex *\fIif_nameindex\fP(void);
.fi
.SH DESCRIPTION
The
\fIif_nameindex\fR()
function shall return an array of
.IR if_nameindex
structures, one structure per interface. The end of the array is
indicated by a structure with an
.IR if_index
field of zero and an
.IR if_name
field of NULL.
.P
Applications should call
\fIif_freenameindex\fR()
to release the memory that may be dynamically allocated by this
function, after they have finished using it.
.SH "RETURN VALUE"
An array of structures identifying local interfaces. A null pointer is
returned upon an error, with
.IR errno
set to indicate the error.
.SH ERRORS
The
\fIif_nameindex\fR()
function may fail if:
.TP
.BR ENOBUFS
Insufficient resources are available to complete the function.
.LP
.IR "The following sections are informative."
.SH "EXAMPLES"
None.
.SH "APPLICATION USAGE"
None.
.SH "RATIONALE"
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIgetsockopt\fR\^(\|)",
.IR "\fIif_freenameindex\fR\^(\|)",
.IR "\fIif_indextoname\fR\^(\|)",
.IR "\fIif_nametoindex\fR\^(\|)",
.IR "\fIsetsockopt\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2008,
.IR "\fB<net_if.h>\fP"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .

Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .