C语言实现TCP通信

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#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <netinet/in.h>

#define SERVPORT 3333
#define BACKLOG 10
#define MAX_CONNECTED_NO 10
#define MAXDATASIZE 5

int main() {
    struct sockaddr_in server_sockaddr, client_sockaddr;
    int sin_size, recvbytes;
    int sockfd, client_fd;
    char buf[MAXDATASIZE];
    
    if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("socket");
        exit(1);
    }
    printf("socket success! sockfd = %d\n", sockfd);
    
    server_sockaddr.sin_family = AF_INET;
    server_sockaddr.sin_port = htons(SERVPORT);
    server_sockaddr.sin_addr.s_addr = INADDR_ANY;
    bzero(&(server_sockaddr.sin_zero), 8);
    
    if(bind(sockfd, (struct sockaddr *)&server_sockaddr, sizeof(struct sockaddr)) == -1) {
        perror("bind");
        exit(1);
    }
    printf("bind success!\n");
    
    if(listen(sockfd, BACKLOG) == -1) {
        perror("listen");
        exit(1);
    }
    printf("listening!\n");
    
    if((client_fd = accept(sockfd, (struct sockaddr *)&client_sockaddr, &sin_size)) == -1) {
        perror("accept");
        exit(1);
    }
    
    if((recvbytes = recv(client_fd, buf, MAXDATASIZE, 0)) == -1) {
        perror("recv");
        exit(1);
    }
    //cout << "received a connection: " << buf << endl;
    close(sockfd);
    return 0;
}

#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>

#define SERVPORT 3333
#define MAXDATASIZE 100

int main(int argc, char *argv[]) {
    int sockfd, sendbytes;
    char buf[MAXDATASIZE];
    struct hostent *host;
    struct sockaddr_in serv_addr;
    if(argv < 2) {
        fprintf(stderr, "Please enter the server is hostname!\n");
        exit(1);
    }
    
    if((host = gethostbyname(argv[1])) == NULL) {
        perror("gethostbyname");
        exit(1);
    }
    
    if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("socket");
        exit(1);
    }
    
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(SERVPORT);
    serv_addr.sin_addr = *((struct in_addr *)host->h_addr);
    bzero(&(serv_addr.sin_zero), 8);
    
    if(connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(struct sockaddr)) == -1) {
        perror("connect");
        exit(1);
    }
    
    if((sendbytes = send(sockfd, "hello", 5, 0)) == -1) {
        perror("send");
        exit(1);
    }
    
    char revcBuf[100];
    recv(sockfd, revcBuf, 100, 0);
    close(sockfd);
    return 0;
}

C语言实现TCP通信

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原文地址：http://blog.csdn.net/u010470972/article/details/46547195