linux fin_wait

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

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

    struct sockaddr_in server_addr;
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(8080);
    inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr);

    if (connect(sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) == -1) {
        perror("connect");
        close(sock);
        exit(EXIT_FAILURE);
    }

    struct linger so_linger;
    so_linger.l_onoff = 1;
    so_linger.l_linger = 0;
    setsockopt(sock, SOL_SOCKET, SO_LINGER, &so_linger, sizeof(so_linger));

    // 发送数据...

    close(sock);
    return 0;
}