Home Man
Search
Today's Posts
Register

Linux & Unix Commands - Search Man Pages

RedHat 9 (Linux i386) - man page for socket (redhat section 3pm)

Socket(3pm)			 Perl Programmers Reference Guide		      Socket(3pm)

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', 'tcp');
	   $sin = sockaddr_in($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.

       Also, some common socket "newline" constants are provided: the constants "CR", "LF", and
       "CRLF", as well as $CR, $LF, and $CRLF, which map to "\015", "\012", and "\015\012".  If
       you do not want to use the literal characters in your programs, then use the constants
       provided here.  They are not exported by default, but can be imported individually, and
       with the ":crlf" export tag:

	   use Socket qw(:DEFAULT :crlf);

       In addition, some structure manipulation functions are available:

       inet_aton HOSTNAME
	   Takes a string giving the name of a host, and translates that to an opaque string (if
	   programming in C, struct in_addr). 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.

	   For portability do not assume that the result of inet_aton() is 32 bits wide, in other
	   words, that it would contain only the IPv4 address in network order.

       inet_ntoa IP_ADDRESS
	   Takes a string (an opaque string as returned by inet_aton(), or a v-string represent-
	   ing the four octets of the IPv4 address in network order) and translates it into a
	   string of the form 'd.d.d.d' where the 'd's are numbers less than 256 (the normal
	   human-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 pro-
	   tocols to solicit information from all servers on the same LAN cable.  Normally equiv-
	   alent 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_family SOCKADDR
	   Takes a sockaddr structure (as returned by pack_sockaddr_in(), pack_sockaddr_un() or
	   the perl builtin functions getsockname() and getpeername()) and returns the address
	   family tag.	It will match the constant AF_INET for a sockaddr_in and AF_UNIX for a
	   sockaddr_un.  It can be used to figure out what unpacker to use for a sockaddr of
	   unknown type.

       sockaddr_in PORT, ADDRESS
       sockaddr_in SOCKADDR_IN
	   In a list 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 SOCK-
	   ADDR_IN and returns it.  If this is confusing, use pack_sockaddr_in() and unpack_sock-
	   addr_in() explicitly.

       pack_sockaddr_in PORT, IP_ADDRESS
	   Takes two arguments, a port number and an opaque string, IP_ADDRESS (as returned by
	   inet_aton(), or a v-string).  Returns the sockaddr_in structure with those arguments
	   packed in with AF_INET filled in.  For Internet domain sockets, this structure is nor-
	   mally what you need for the arguments in bind(), connect(), and send(), and is also
	   returned by getpeername(), getsockname() and recv().

       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 an opaque string representing the IP address (you can
	   use inet_ntoa() to convert the address to the four-dotted numeric format).  Will croak
	   if the structure does not have AF_INET in the right place.

       sockaddr_un PATHNAME
       sockaddr_un SOCKADDR_UN
	   In a list 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.

perl v5.8.0				    2002-06-01				      Socket(3pm)


All times are GMT -4. The time now is 10:56 AM.

Unix & Linux Forums Content Copyrightę1993-2018. All Rights Reserved.
UNIX.COM Login
Username:
Password:  
Show Password