Linux C 文件傳輸實戰：基於 TCP Socket 的服務端與客戶端完整代碼

編輯：關於C語言

架構概覽

協議：TCP（SOCK_STREAM）
端口：6666
緩衝區：1024 字節
流程：客戶端發送文件名 → 服務端讀取文件分塊發送 → 客戶端接收寫入文件

服務端核心代碼

#include 
#include 
#include 
#include 
#include 

#define PORT 6666
#define BACKLOG 20
#define BUF_SIZE 1024
#define NAME_MAX 512

int main() {
    struct sockaddr_in server_addr = {0};
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(PORT);

    int server_socket = socket(PF_INET, SOCK_STREAM, 0);
    if (server_socket < 0) { perror("socket"); exit(1); }

    if (bind(server_socket, (struct sockaddr*)&server_addr, sizeof(server_addr))) {
        perror("bind"); exit(1);
    }
    if (listen(server_socket, BACKLOG)) { perror("listen"); exit(1); }

    while (1) {
        struct sockaddr_in client_addr;
        socklen_t len = sizeof(client_addr);
        int client_socket = accept(server_socket, (struct sockaddr*)&client_addr, &len);
        if (client_socket < 0) { perror("accept"); break; }

        char buffer[BUF_SIZE] = {0};
        int r = recv(client_socket, buffer, BUF_SIZE, 0);
        if (r <= 0) { close(client_socket); continue; }

        char filename[NAME_MAX+1] = {0};
        strncpy(filename, buffer, strlen(buffer) > NAME_MAX ? NAME_MAX : strlen(buffer));

        FILE *fp = fopen(filename, "r");
        if (!fp) { printf("File %s Not Found\n", filename); }
        else {
            int block_len;
            while ((block_len = fread(buffer, 1, BUF_SIZE, fp)) > 0) {
                if (send(client_socket, buffer, block_len, 0) < 0) { perror("send"); break; }
            }
            fclose(fp);
            printf("File %s Transfer Finished\n", filename);
        }
        close(client_socket);
    }
    close(server_socket);
    return 0;
}

客戶端核心代碼

#include 
#include 
#include 
#include 
#include 
#include 

#define PORT 6666
#define BUF_SIZE 1024
#define NAME_MAX 512

int main(int argc, char **argv) {
    if (argc != 2) { fprintf(stderr, "Usage: %s ServerIP\n", argv[0]); exit(1); }

    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) { perror("socket"); exit(1); }

    struct sockaddr_in server_addr = {0};
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    if (inet_aton(argv[1], &server_addr.sin_addr) == 0) { fprintf(stderr, "Invalid IP\n"); exit(1); }

    if (connect(sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        perror("connect"); exit(1);
    }

    char filename[NAME_MAX+1] = {0};
    printf("Please Input File Name On Server: ");
    scanf("%s", filename);

    send(sock, filename, strlen(filename), 0);

    FILE *fp = fopen(filename, "w");
    if (!fp) { perror("fopen"); exit(1); }

    char buffer[BUF_SIZE];
    int len;
    while ((len = recv(sock, buffer, BUF_SIZE, 0)) > 0) {
        fwrite(buffer, 1, len, fp);
    }
    fclose(fp);
    close(sock);
    printf("Receive File %s Finished\n", filename);
    return 0;
}