Socket(3) Socket(3)
NAME
Socket, sockaddr_in, sockaddr_un, inet_aton, inet_ntoa - load the C
socket.h defines and structure manipulators
SYNOPSIS
use Socket;
$proto = getprotobyname('udp');
socket(Socket_Handle, PF_INET, SOCK_DGRAM, $proto);
$iaddr = gethostbyname('hishost.com');
$port = getservbyname('time', 'udp');
$sin = sockaddr_in($port, $iaddr);
send(Socket_Handle, 0, 0, $sin);
$proto = getprotobyname('tcp');
socket(Socket_Handle, PF_INET, SOCK_STREAM, $proto);
$port = getservbyname('smtp');
$sin = sockaddr_in($port,inet_aton("127.1"));
$sin = sockaddr_in(7,inet_aton("localhost"));
$sin = sockaddr_in(7,INADDR_LOOPBACK);
connect(Socket_Handle,$sin);
($port, $iaddr) = sockaddr_in(getpeername(Socket_Handle));
$peer_host = gethostbyaddr($iaddr, AF_INET);
$peer_addr = inet_ntoa($iaddr);
$proto = getprotobyname('tcp');
socket(Socket_Handle, PF_UNIX, SOCK_STREAM, $proto);
unlink('/tmp/usock');
$sun = sockaddr_un('/tmp/usock');
connect(Socket_Handle,$sun);
DESCRIPTION
This module is just a translation of the C socket.h file. Unlike the old
mechanism of requiring a translated socket.ph file, this uses the h2xs
program (see the Perl source distribution) and your native C compiler.
This means that it has a far more likely chance of getting the numbers
right. This includes all of the commonly used pound-defines like
AF_INET, SOCK_STREAM, etc.
In addition, some structure manipulation functions are available:
inet_aton HOSTNAME
Takes a string giving the name of a host, and translates that to the
4-byte string (structure). Takes arguments of both the
'rtfm.mit.edu' type and '18.181.0.24'. If the host name cannot be
resolved, returns undef. For multi-homed hosts (hosts with more than
one address), the first address found is returned.
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Socket(3) Socket(3)
inet_ntoa IP_ADDRESS
Takes a four byte ip address (as returned by inet_aton()) and
translates it into a string of the form 'd.d.d.d' where the 'd's are
numbers less than 256 (the normal readable four dotted number
notation for internet addresses).
INADDR_ANY
Note: does not return a number, but a packed string.
Returns the 4-byte wildcard ip address which specifies any of the
hosts ip addresses. (A particular machine can have more than one ip
address, each address corresponding to a particular network
interface. This wildcard address allows you to bind to all of them
simultaneously.) Normally equivalent to inet_aton('0.0.0.0').
INADDR_BROADCAST
Note: does not return a number, but a packed string.
Returns the 4-byte 'this-lan' ip broadcast address. This can be
useful for some protocols to solicit information from all servers on
the same LAN cable. Normally equivalent to
inet_aton('255.255.255.255').
INADDR_LOOPBACK
Note - does not return a number.
Returns the 4-byte loopback address. Normally equivalent to
inet_aton('localhost').
INADDR_NONE
Note - does not return a number.
Returns the 4-byte 'invalid' ip address. Normally equivalent to
inet_aton('255.255.255.255').
sockaddr_in PORT, ADDRESS
sockaddr_in SOCKADDR_IN
In an array context, unpacks its SOCKADDR_IN argument and returns an
array consisting of (PORT, ADDRESS). In a scalar context, packs its
(PORT, ADDRESS) arguments as a SOCKADDR_IN and returns it. If this
is confusing, use pack_sockaddr_in() and unpack_sockaddr_in()
explicitly.
pack_sockaddr_in PORT, IP_ADDRESS
Takes two arguments, a port number and a 4 byte IP_ADDRESS (as
returned by inet_aton()). Returns the sockaddr_in structure with
those arguments packed in with AF_INET filled in. For internet
domain sockets, this structure is normally what you need for the
arguments in bind(), connect(), and send(), and is also returned by
getpeername(), getsockname() and recv().
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Socket(3) Socket(3)
unpack_sockaddr_in SOCKADDR_IN
Takes a sockaddr_in structure (as returned by pack_sockaddr_in())
and returns an array of two elements: the port and the 4-byte ip-
address. Will croak if the structure does not have AF_INET in the
right place.
sockaddr_un PATHNAME
sockaddr_un SOCKADDR_UN
In an array context, unpacks its SOCKADDR_UN argument and returns an
array consisting of (PATHNAME). In a scalar context, packs its
PATHNAME arguments as a SOCKADDR_UN and returns it. If this is
confusing, use pack_sockaddr_un() and unpack_sockaddr_un()
explicitly. These are only supported if your system has <sys/un.h>.
pack_sockaddr_un PATH
Takes one argument, a pathname. Returns the sockaddr_un structure
with that path packed in with AF_UNIX filled in. For unix domain
sockets, this structure is normally what you need for the arguments
in bind(), connect(), and send(), and is also returned by
getpeername(), getsockname() and recv().
unpack_sockaddr_un SOCKADDR_UN
Takes a sockaddr_un structure (as returned by pack_sockaddr_un())
and returns the pathname. Will croak if the structure does not have
AF_UNIX in the right place.
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