SendOutOfBandData.cpp

#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<assert.h>
#include<stdio.h>
#include<unistd.h>
#include<string.h>
#include<stdlib.h>

int main(int argc,char*argv[])
{
    if (argc <= 2)
    {
        /* code */
        printf("usage:%s ip_address port_number\n",basename(argv[0]));
        return 1;
    }

    const char*ip = argv[1];
    int port =atoi(argv[2]);
    struct sockaddr_in server_address;
    bzero(&server_address,sizeof(server_address));
    server_address.sin_family = AF_INET;
    inet_pton(AF_INET,ip,&server_address.sin_addr);
    server_address.sin_port = htons(port);
    int sockfd = socket(PF_INET,SOCK_STREAM,0);
    assert(sockfd >=  0);

    if (connect(sockfd,(struct sockaddr*)& server_address
    ,sizeof(server_address))< 0)
    {
        /* code */
        printf("connection failed\n");
    }
    else
    {
        /* code */
        const char* oob_data = "abc";
        const char* normal_data = "123";
        send(sockfd,normal_data,strlen(normal_data),0);
        send(sockfd,oob_data,strlen(oob_data),MSG_OOB);
        send(sockfd,normal_data,strlen(normal_data),0);
    }
    close(sockfd);
    return 0;
}