c语言scoket实现聊天和文件传送功能的完整代码

以下是一个简单的C语言Socket实现聊天和文件传输功能的完整代码示例。

Server端代码：

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

#define PORT 8000

void handle_client(int client_sock, struct sockaddr_in client_addr)
{
    char buffer[1024];
    int n;

    printf("[NEW CONNECTION] %s:%d connected.\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));

    while (1)
    {
        memset(buffer, 0, sizeof(buffer));
        n = recv(client_sock, buffer, sizeof(buffer), 0);
        if (n <= 0)
        {
            printf("[DISCONNECTED] %s:%d disconnected.\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
            break;
        }
        else if (strcmp(buffer, "quit") == 0)
        {
            printf("[DISCONNECTED] %s:%d disconnected.\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
            break;
        }
        else if (strcmp(buffer, "send_file") == 0)
        {
            char filename[1024];
            memset(filename, 0, sizeof(filename));
            int filesize;
            n = recv(client_sock, filename, sizeof(filename), 0);
            n = recv(client_sock, &filesize, sizeof(filesize), 0);
            int file_fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
            int total_recv = 0, recv_size;
            while (total_recv < filesize)
            {
                memset(buffer, 0, sizeof(buffer));
                recv_size = recv(client_sock, buffer, sizeof(buffer), 0);
                if (recv_size <= 0)
                {
                    break;
                }
                write(file_fd, buffer, recv_size);
                total_recv += recv_size;
            }
            close(file_fd);
            printf("[FILE RECEIVED] File %s received from %s:%d.\n", filename, inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
        }
        else
        {
            printf("[%s:%d] %s\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port), buffer);
            send(client_sock, "Server received.", strlen("Server received."), 0);
        }
    }

    close(client_sock);
}

int main()
{
    int server_sock, client_sock;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len;

    server_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (server_sock < 0)
    {
        perror("socket error");
        exit(EXIT_FAILURE);
    }

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(PORT);

    if (bind(server_sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0)
    {
        perror("bind error");
        exit(EXIT_FAILURE);
    }

    if (listen(server_sock, 5) < 0)
    {
        perror("listen error");
        exit(EXIT_FAILURE);
    }

    printf("[LISTENING] Server is listening on %s:%d.\n", inet_ntoa(server_addr.sin_addr), ntohs(server_addr.sin_port));

    while (1)
    {
        client_addr_len = sizeof(client_addr);
        client_sock = accept(server_sock, (struct sockaddr *)&client_addr, &client_addr_len);
        if (client_sock < 0)
        {
            perror("accept error");
            exit(EXIT_FAILURE);
        }

        handle_client(client_sock, client_addr);
    }

    close(server_sock);

    return 0;
}

Client端代码：

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

#define PORT 8000

void send_file(int sock, char *filename)
{
    char buffer[1024];
    int n, filesize;
    memset(buffer, 0, sizeof(buffer));
    sprintf(buffer, "send_file");
    send(sock, buffer, strlen(buffer), 0);
    memset(buffer, 0, sizeof(buffer));
    strcpy(buffer, filename);
    send(sock, buffer, strlen(buffer), 0);
    filesize = lseek(open(filename, O_RDONLY), 0, SEEK_END);
    lseek(open(filename, O_RDONLY), 0, SEEK_SET);
    send(sock, &filesize, sizeof(filesize), 0);
    int total_send = 0, send_size;
    while (total_send < filesize)
    {
        memset(buffer, 0, sizeof(buffer));
        send_size = read(open(filename, O_RDONLY), buffer, sizeof(buffer));
        if (send_size <= 0)
        {
            break;
        }
        send(sock, buffer, send_size, 0);
        total_send += send_size;
    }
    printf("[FILE SENT] File %s sent to server.\n", filename);
}

int main()
{
    int sock;
    struct sockaddr_in server_addr;

    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0)
    {
        perror("socket error");
        exit(EXIT_FAILURE);
    }

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    server_addr.sin_port = htons(PORT);

    if (connect(sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0)
    {
        perror("connect error");
        exit(EXIT_FAILURE);
    }

    char buffer[1024];
    int n;

    while (1)
    {
        memset(buffer, 0, sizeof(buffer));
        printf("Enter your message or file path: ");
        fgets(buffer, sizeof(buffer), stdin);
        buffer[strlen(buffer) - 1] = '\0';
        if (strcmp(buffer, "quit") == 0)
        {
            send(sock, buffer, strlen(buffer), 0);
            break;
        }
        else if (access(buffer, F_OK) == 0)
        {
            send_file(sock, buffer);
        }
        else
        {
            send(sock, buffer, strlen(buffer), 0);
            n = recv(sock, buffer, sizeof(buffer), 0);
            printf("%s\n", buffer);
        }
    }

    close(sock);

    return 0;
}

这个例子使用了C语言的socket库来实现基本的聊天和文件传输功能。在Server端，我们使用一个while循环来接受来自客户端的消息，并根据消息类型进行处理。如果消息是"quit"，则关闭客户端连接；如果消息是"send_file"，则接收文件名和文件大小，然后接收文件并保存到本地；否则，将消息打印出来并发送一个确认消息回客户端。

在Client端，我们使用一个while循环来等待用户输入。如果用户输入的是"quit"，则关闭客户端连接；如果用户输入的是一个文件路径，则发送"send_file"消息给服务器，并发送文件；否则，将用户输入的消息发送给服务器，并等待服务器的确认消息。