INET_NTOP

Section: Linux Programmer's Manual (3)
Updated: 2008-11-11
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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 address 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 inet_ntoa(3) function to support multiple address families, inet_ntoa(3) is now considered to be deprecated in favor of inet_ntop(). The following address families are currently supported:

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 format, "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 appropriate 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 returned 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.
 

CONFORMING TO

POSIX.1-2001. 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 inet_pton(3).  

SEE ALSO

getnameinfo(3), inet(3), inet_pton(3)  

COLOPHON

This page is part of release 3.22 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.