1*62783Sbostic .\" Copyright (c) 1986, 1993 2*62783Sbostic .\" The Regents of the University of California. All rights reserved. 348154Sbostic .\" 448154Sbostic .\" %sccs.include.redist.roff% 548154Sbostic .\" 6*62783Sbostic .\" @(#)dgramsend.c 8.1 (Berkeley) 06/08/93 748154Sbostic .\" 827700Smckusick #include <sys/types.h> 927700Smckusick #include <sys/socket.h> 1027700Smckusick #include <netinet/in.h> 1127700Smckusick #include <netdb.h> 1227700Smckusick #include <stdio.h> 1327700Smckusick 1427700Smckusick #define DATA "The sea is calm tonight, the tide is full . . ." 1527700Smckusick 1627700Smckusick /* 1727700Smckusick * Here I send a datagram to a receiver whose name I get from the command 1827700Smckusick * line arguments. The form of the command line is dgramsend hostname 1927700Smckusick * portnumber 2027700Smckusick */ 2127700Smckusick 2227700Smckusick main(argc, argv) 2327883Skarels int argc; 2427883Skarels char *argv[]; 2527700Smckusick { 2627883Skarels int sock; 2727700Smckusick struct sockaddr_in name; 2827700Smckusick struct hostent *hp, *gethostbyname(); 2927700Smckusick 3027700Smckusick /* Create socket on which to send. */ 3127700Smckusick sock = socket(AF_INET, SOCK_DGRAM, 0); 3227700Smckusick if (sock < 0) { 3327700Smckusick perror("opening datagram socket"); 3427883Skarels exit(1); 3527700Smckusick } 3627700Smckusick /* 3727700Smckusick * Construct name, with no wildcards, of the socket to send to. 3827700Smckusick * Getnostbyname() returns a structure including the network address 3927700Smckusick * of the specified host. The port number is taken from the command 4027700Smckusick * line. 4127700Smckusick */ 4227700Smckusick hp = gethostbyname(argv[1]); 4327883Skarels if (hp == 0) { 4427883Skarels fprintf(stderr, "%s: unknown host\n", argv[1]); 4527883Skarels exit(2); 4627883Skarels } 4727883Skarels bcopy(hp->h_addr, &name.sin_addr, hp->h_length); 4827700Smckusick name.sin_family = AF_INET; 4927700Smckusick name.sin_port = htons(atoi(argv[2])); 5027700Smckusick /* Send message. */ 5127883Skarels if (sendto(sock, DATA, sizeof(DATA), 0, &name, sizeof(name)) < 0) 5227700Smckusick perror("sending datagram message"); 5327700Smckusick close(sock); 5427700Smckusick } 55