inet_ntop(3) Linux Programmer's Manual inet_ntop(3)
inet_ntop - Parse network address structures
const char *inet_ntop(int af, const void *src,
char *dst, socklen_t cnt);
This function converts the network address structure src in the af
address family into a character string, which is copied to a character
buffer dst, which is cnt bytes long.
inet_ntop(3) 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(3). The following address families are currently
src points to a struct in_addr (network byte order format) which
is converted to an IPv4 network address in the dotted-quad for-
mat, "ddd.ddd.ddd.ddd". The buffer dst must be at least
INET_ADDRSTRLEN bytes long.
src points to a struct in6_addr (network byte order format)
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.
inet_ntop() returns a non-null pointer to dst. NULL is returned if
there was an error, with errno set to EAFNOSUPPORT if af was not set to
a valid address family, or to ENOSPC if the converted address string
would exceed the size of dst given by the cnt argument.
POSIX.1-2001. Note that RFC 2553 defines a prototype where the last
parameter cnt is of type size_t. Many systems follow RFC 2553. Glibc
2.0 and 2.1 have size_t, but 2.2 has socklen_t.
AF_INET6 converts IPv6-mapped IPv4 addresses into an IPv6 format.
Linux Man Page 2000-12-18 inet_ntop(3)