pack_sockaddr_in6#

Build a packed sockaddr_in6 from a port, a 16-byte IPv6 address, and optional scope and flow-info fields.

Synopsis#

my $sin6 = pack_sockaddr_in6($port, $packed_ipv6);
my $sin6 = pack_sockaddr_in6($port, $packed_ipv6, $scope_id, $flowinfo);

What you get back#

A fixed-size byte string matching the platform’s struct sockaddr_in6, ready for bind or connect.

Examples#

my $addr = inet_pton(AF_INET6, "::1");
my $sin6 = pack_sockaddr_in6(443, $addr);
connect($sock, $sin6) or die $!;

## Link-local address with scope index for eth0.

my $scope = scalar getsockopt(...);   # or from if_nametoindex
my $sin6  = pack_sockaddr_in6(5353, inet_pton(AF_INET6, "fe80::1"), $scope);

Edge cases#

  • $scope_id and $flowinfo default to 0 when omitted.

  • An address argument shorter than 16 bytes leaves the address field zeroed (i.e. ::).

  • Port and flow-info are truncated to 16 and 32 bits respectively.

Differences from upstream#

Fully compatible with upstream Socket.

See also#

  • unpack_sockaddr_in6 — reverse direction.

  • sockaddr_in6 — dual-mode shortcut that dispatches on arg count.

  • pack_sockaddr_in — IPv4 counterpart.

  • inet_pton — usual source of the address argument.