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Annotation of cci/usr/src/man/man4/udp.4p, revision 1.1.1.1

1.1       root        1: .TH UDP 4P "25 March 1982"
                      2: .UC 4
                      3: .SH NAME
                      4: udp \- Internet User Datagram Protocol
                      5: .SH SYNOPSIS
                      6: .B #include <sys/socket.h>
                      7: .br
                      8: .B #include <netinet/in.h>
                      9: .PP
                     10: .B s = socket(AF_INET, SOCK_DGRAM, 0);
                     11: .SH DESCRIPTION
                     12: UDP is a simple, unreliable datagram protocol which is used
                     13: to support the SOCK_DGRAM abstraction for the Internet
                     14: protocol family.  UDP sockets are connectionless, and are
                     15: normally used with the
                     16: .I sendto 
                     17: and
                     18: .IR recvfrom 
                     19: calls, though the
                     20: .IR connect (2)
                     21: call may also be used to fix the destination for future
                     22: packets (in which case the 
                     23: .IR recv (2)
                     24: or
                     25: .IR read (2)
                     26: and 
                     27: .IR send (2)
                     28: or
                     29: .IR write(2)
                     30: system calls may be used).
                     31: .PP
                     32: UDP address formats are identical to those used by
                     33: TCP. In particular UDP provides a port identifier in addition
                     34: to the normal Internet address format.  Note that the UDP port
                     35: space is separate from the TCP port space (i.e. a UDP port
                     36: may not be \*(lqconnected\*(rq to a TCP port).  In addition broadcast
                     37: packets may be sent (assuming the underlying network supports
                     38: this) by using a reserved \*(lqbroadcast address\*(rq; this address
                     39: is network interface dependent.
                     40: .SH DIAGNOSTICS
                     41: A socket operation may fail with one of the following errors returned:
                     42: .TP 15
                     43: [EISCONN]
                     44: when trying to establish a connection on a socket which
                     45: already has one, or when trying to send a datagram with the destination
                     46: address specified and the socket is already connected;
                     47: .TP 15
                     48: [ENOTCONN]
                     49: when trying to send a datagram, but
                     50: no destination address is specified, and the socket hasn't been
                     51: connected;
                     52: .TP 15
                     53: [ENOBUFS]
                     54: when the system runs out of memory for
                     55: an internal data structure;
                     56: .TP 15
                     57: [EADDRINUSE]
                     58: when an attempt
                     59: is made to create a socket with a port which has already been
                     60: allocated;
                     61: .TP 15
                     62: [EADDRNOTAVAIL]
                     63: when an attempt is made to create a 
                     64: socket with a network address for which no network interface
                     65: exists.
                     66: .SH SEE ALSO
                     67: send(2),
                     68: recv(2),
                     69: intro(4N),
                     70: inet(4F)

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