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inet_ntop
<html> <head> <title>inet_ntop</title> <META NAME="KEYWORDS" CONTENT="inet_ntop"> </head> <body BGCOLOR="#ffffff" LINK="#0000ff" VLINK="#0000ff" ALINK="#0000ff" TEXT="#000000"> <center> <h1><b>inet_ntop</b></h1></center> <PRE> <STRONG><A HREF="/man3/INET_NTOP">INET_NTOP(3)</A></STRONG> Linux Programmer's Manual <STRONG><A HREF="/man3/INET_NTOP">INET_NTOP(3)</A></STRONG> NAME inet_ntop - convert IPv4 and IPv6 addresses from binary to text form SYNOPSIS #include <arpa/inet.h> const char *inet_ntop(int af, const void *src, char *dst, socklen_t size); DESCRIPTION This function converts the network address structure src in the af ad- dress family into a character string. The resulting string is copied to the buffer pointed to by dst, which must be a non-null pointer. The caller specifies the number of bytes available in this buffer in the argument size. inet_ntop() extends the <STRONG><A HREF="/man3/inet_ntoa">inet_ntoa(3)</A></STRONG> function to support multiple ad- dress families, <STRONG><A HREF="/man3/inet_ntoa">inet_ntoa(3)</A></STRONG> is now considered to be deprecated in fa- vor of inet_ntop(). The following address families are currently sup- ported: AF_INET src points to a struct in_addr (in network byte order) which is converted to an IPv4 network address in the dotted-decimal for- mat, "ddd.ddd.ddd.ddd". The buffer dst must be at least INET_ADDRSTRLEN bytes long. AF_INET6 src points to a struct in6_addr (in network byte order) which is converted to a representation of this address in the most appro- priate IPv6 network address format for this address. The buffer dst must be at least INET6_ADDRSTRLEN bytes long. RETURN VALUE On success, inet_ntop() returns a non-null pointer to dst. NULL is re- turned if there was an error, with errno set to indicate the error. ERRORS EAFNOSUPPORT af was not a valid address family. ENOSPC The converted address string would exceed the size given by size. 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 | +------------+---------------+----------------+ |inet_ntop() | Thread safety | MT-Safe locale | +------------+---------------+----------------+ CONFORMING TO POSIX.1-2001, POSIX.1-2008. Note that RFC 2553 defines a prototype where the last argument size is of type size_t. Many systems follow RFC 2553. Glibc 2.0 and 2.1 have size_t, but 2.2 and later have socklen_t. BUGS AF_INET6 converts IPv4-mapped IPv6 addresses into an IPv6 format. EXAMPLE See <STRONG><A HREF="/man3/inet_pton">inet_pton(3)</A></STRONG>. SEE ALSO <STRONG><A HREF="/man3/getnameinfo">getnameinfo(3)</A></STRONG>, <STRONG><A HREF="/man3/inet">inet(3)</A></STRONG>, <STRONG><A HREF="/man3/inet_pton">inet_pton(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/. Linux 2017-09-15 <STRONG><A HREF="/man3/INET_NTOP">INET_NTOP(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>