linux 中断connect

#include <signal.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

void handle_signal(int signum) {
    // 处理信号的逻辑
}

int main() {
    struct sigaction sa;
    sa.sa_handler = handle_signal;
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = 0;
    sigaction(SIGINT, &sa, NULL);

    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
    struct sockaddr_in serv_addr;
    // 设置服务器地址...

    if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == -1) {
        perror("connect failed");
        close(sockfd);
        return 1;
    }

    // 连接成功后的操作...

    close(sockfd);
    return 0;
}

#include <fcntl.h>
#include <sys/select.h>

int set_nonblocking(int sockfd) {
    int flags = fcntl(sockfd, F_GETFL, 0);
    if (flags == -1) return -1;
    flags |= O_NONBLOCK;
    return fcntl(sockfd, F_SETFL, flags);
}

int main() {
    int sockfd = socket(AF_INET, SOCK_STREAM, 0);
    set_nonblocking(sockfd);

    struct sockaddr_in serv_addr;
    // 设置服务器地址...

    if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == -1) {
        if (errno != EINPROGRESS) {
            perror("connect failed");
            close(sockfd);
            return 1;
        }
    }

    fd_set writefds;
    FD_ZERO(&writefds);
    FD_SET(sockfd, &writefds);

    struct timeval timeout;
    timeout.tv_sec = 5; // 设置超时时间
    timeout.tv_usec = 0;

    if (select(sockfd + 1, NULL, &writefds, NULL, &timeout) > 0) {
        int so_error;
        socklen_t len = sizeof(so_error);
        getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &so_error, &len);
        if (so_error == 0) {
            // 连接成功
        } else {
            perror("connect error");
        }
    } else {
        perror("select timeout");
    }

    close(sockfd);
    return 0;
}