af_inet.c

实战Linux socket编程例题源代码

/* af_inet.c:
 * 
 * Establishing a Specific AF_INET
 * Socket Address:
 */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>

/*
 * This function reports the error and
 * exits back to the shell :
 */
static void
bail(const char *on_what) {
    perror(on_what);
    exit(1);
}

int
main(int argc,char **argv,char **envp) {
    int z;           /* Status return code */
    int sck_inet;               /* Socket  */
    struct sockaddr_in adr_inet;/* AF_INET */
    int len_inet;               /* length  */
    const unsigned char IPno[] = {
        127, 0, 0, 23    /* Local loopback */
    };

    /* Create an IPv4 Internet Socket */
    sck_inet = socket(AF_INET,SOCK_STREAM,0);

    if ( sck_inet == -1 )
        bail("socket()");

    /* Create an AF_INET address */
    memset(&adr_inet,0,sizeof adr_inet);

    adr_inet.sin_family = AF_INET;
    adr_inet.sin_port = htons(9000);
    memcpy(&adr_inet.sin_addr.s_addr,IPno,4);
    len_inet = sizeof adr_inet;

    /* Now bind the address to the socket */
    z = bind(sck_inet,
        (struct sockaddr *)&adr_inet,
        len_inet);

    if ( z == -1 )
        bail("bind()");

    /* Display all of our bound sockets */
    system("netstat -pa --tcp 2>/dev/null | "
        "sed -n '1,/^Proto/p;/af_inet/p'");

    close(sck_inet);
    return 0;
}