makeaddr.c

实战的linux socket编程--示例源码

/* makeaddr.c:
 * 
 * Demonstrate inet_lnaof, inet_netof
 * and inet_makeaddr(3) functions;
 */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int
main(int argc,char **argv) {
    int x;
    struct sockaddr_in adr_inet;/* AF_INET */
    const char *addr[] = {
        "44.135.86.12",
        "127.0.0.1",
        "172.16.23.95",
        "192.168.9.1"
    };
    unsigned long net, hst;

    for ( x=0; x<4; ++x ) {
        /*
         * Create a socket address:
         */
        memset(&adr_inet,0,sizeof adr_inet);
        adr_inet.sin_family = AF_INET;
        adr_inet.sin_port = htons(9000);
        if ( !inet_aton(addr[x],
                  &adr_inet.sin_addr) )
            puts("bad address.");

        /*
         * Split address into Host & Net ID
         */
        hst = inet_lnaof(adr_inet.sin_addr);
        net = inet_netof(adr_inet.sin_addr);

        printf("%14s : net=0x%08lX host=0x%08lX\n",
            inet_ntoa(adr_inet.sin_addr),net,hst);

        /*
         * Zero the address to prove later that
         * we can reconstruct this value :
         */
        memset(&adr_inet,0,sizeof adr_inet);
        adr_inet.sin_family = AF_INET;
        adr_inet.sin_port = htons(9000);

        adr_inet.sin_addr =
            inet_makeaddr(net,hst);

        /*
         * Now display the reconstructed
         * address :
         */
        printf("%14s : %s\n\n",
            "inet_makeaddr",
            inet_ntoa(adr_inet.sin_addr));
    }

    return 0;
}