inet_ntop(3) — Linux manual page


INET_NTOP(3)            Linux Programmer's Manual           INET_NTOP(3)

NAME         top

       inet_ntop - convert IPv4 and IPv6 addresses from binary to text

SYNOPSIS         top

       #include <arpa/inet.h>

       const char *inet_ntop(int af, const void *restrict src,
                             char *restrict dst, socklen_t size);

DESCRIPTION         top

       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:

              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.

              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         top

       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

ERRORS         top

              af was not a valid address family.

       ENOSPC The converted address string would exceed the size given
              by size.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see

       │Interface                      Attribute     Value          │
       │inet_ntop()                    │ Thread safety │ MT-Safe locale │

CONFORMING TO         top

       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         top

       AF_INET6 converts IPv4-mapped IPv6 addresses into an IPv6 format.

EXAMPLES         top

       See inet_pton(3).

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 5.13 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

Linux                          2021-03-22                   INET_NTOP(3)

Pages that refer to this page: gethostbyname(3)getipnodebyname(3)getnameinfo(3)inet(3)inet_pton(3)