TCP编程基础

 
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define LISTEN_BACKLOG (5)
#define BUF_SIZE (1500)
#define ACK_STR "ack ok"
void usage(void) {
    printf("*********************************\n");
    printf("./server 本端ip 本端端口\n");
    printf("*********************************\n");
}
int main(int argc, char *argv[]) {
    struct sockaddr_in client;
    struct sockaddr_in server;
    int sock_fd = 0, new_fd = 0;
    int ret = 0;
    socklen_t addrlen = 0;
    char send_buf[BUF_SIZE] = {0};
    char recv_buf[BUF_SIZE] = {0};
    if (argc != 3) {
        usage();
        return -1;
    }
    char *ip = argv[1];
    unsigned short port = atoi(argv[2]);
    printf("ip:port->%s:%u\n", argv[1], port);
    sock_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (sock_fd == -1) {
        perror("socket error");
        return -1;
    }
    memset(&client, 0, sizeof(struct sockaddr_in));
    client.sin_family = AF_INET;
    client.sin_addr.s_addr = inet_addr(ip);
    client.sin_port = htons(port);
    ret = bind(sock_fd, (struct sockaddr *)&client,
sizeof(struct sockaddr));
    if (ret == -1) {
        close(sock_fd);
        perror("bind error");
        return -1;
    }
    ret = listen(sock_fd, LISTEN_BACKLOG);
    if (ret == -1) {
        close(sock_fd);
        perror("listen error");
        return -1;
    }
    addrlen = sizeof(server);
    new_fd = accept(sock_fd, (struct sockaddr *)&server, &addrlen);
    if (new_fd == -1) {
        close(sock_fd);
        perror("accept error");
        return -1;
    }
    int seq = 0;
    while(1) {
        memset(recv_buf, 0, BUF_SIZE);
        ret = recv(new_fd, recv_buf, BUF_SIZE, 0);
        printf("recv len:%d, %s\n", ret, recv_buf);
        memset(send_buf, 0, BUF_SIZE);
        sprintf(send_buf, "%s:%d\n", ACK_STR, seq++);
        ret = send(new_fd, send_buf, strlen(send_buf), 0);
        printf("send len:%d %s\n", ret, send_buf);
    }
    close(sock_fd);
    close(new_fd);
    return 0;
}

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define LISTEN_BACKLOG (5)
#define BUF_SIZE (1500)
#define REQUEST_STR "tcp pack"
void usage(void) {
    printf("*********************************\n");
    printf("./client 对端ip 对端端口\n");
    printf("*********************************\n");
} int main(int argc, char *argv[]) {
    struct sockaddr_in client;
    struct sockaddr_in server;
    int sock_fd = 0;
    int ret = 0;
    socklen_t addrlen = 0;
    char send_buf[BUF_SIZE] = {0};
    char recv_buf[BUF_SIZE] = {0};
    if (argc != 3) {
        usage();
        return -1;
    }
    char *ip = argv[1];
    unsigned short port = atoi(argv[2]);
    printf("ip:port->%s:%u\n", argv[1], port);
    sock_fd = socket(AF_INET, SOCK_STREAM, 0);
    if (sock_fd == -1) {
        perror("socket error");
        return -1;
    }
    memset(&server, 0, sizeof(struct sockaddr_in));
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = inet_addr(ip);
    server.sin_port = htons(port);
    ret = connect(sock_fd, (struct sockaddr *)&server,
sizeof(struct sockaddr));
    if (ret == -1) {
        close(sock_fd);
        perror("connect error");
        return -1;
    }
    int seq = 0;
    while(1) {
        sleep(1);
        memset(send_buf, 0, BUF_SIZE);
        sprintf(send_buf, "%s:%d", REQUEST_STR, seq++);
        send(sock_fd, send_buf, strlen(send_buf), 0);
        printf("send %s\n", send_buf);
        memset(recv_buf, 0, BUF_SIZE);
        recv(sock_fd, recv_buf, BUF_SIZE, 0);
        printf("recv %s\n", recv_buf);
    }
    close(sock_fd);
    return 0;
}

#gcc server.c -o server

#gcc client.c -o client

#./server 本端ip 本端端口

#./client 对端ip 对端端口