inet_ntop man page

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.

Attributes

For an explanation of the terms used in this section, see attributes(7).

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 inet_pton(3).

See Also

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

Colophon

This page is part of release 4.11 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/.

Referenced By

fmt_ip4(3), fmt_ip6(3), gethostbyname(3), getipnodebyname(3), getnameinfo(3), inet(3), inet_pton(3), lwres_net_ntop(3).

2015-08-08 Linux Programmer's Manual