This function converts the character string src into a network address
structure in the af address family, then copies the network address
structure to dst.
inet_pton(3) extends the inet_addr(3) function to support multiple
address families, inet_addr(3) is now considered to be deprecated in
favor of inet_pton(3). The following address families are currently
src points to a character string containing an IPv4
network address in the dotted-quad format, "
ddd.ddd.ddd.ddd". The address is converted to a struct
in_addr and copied to dst, which must be sizeof(struct
in_addr) bytes long.
src points to a character string containing an IPv6
network address in any allowed IPv6 address format. The address is
converted to a struct in6_addr and copied to dst, which must
be sizeof(struct in6_addr) bytes long.
Certain legacy hex and octal formats of AF_INET addresses are not
supported by inet_pton, which rejects them.
inet_pton returns a negative value and sets errno to
EAFNOSUPPORT if af does not contain a valid address family. 0 is
returned if src does not contain a character string representing a
valid network address in the specified address family. A positive value is
returned if the network address was successfully converted.