我有一個簡單的程序來檢查端口是否打開，但是我想縮短套接字連接的超時時間，因為默認值太長了。我不確定如何執(zhí)行此操作。這是代碼：#include <sys/socket.h>#include <sys/time.h>#include <sys/types.h>#include <arpa/inet.h>#include <netinet/in.h>#include <errno.h>#include <fcntl.h>#include <stdio.h>#include <netdb.h>#include <stdlib.h>#include <string.h>#include <unistd.h>int main(int argc, char **argv) {    u_short port;                /* user specified port number */    char addr[1023];             /* will be a copy of the address entered by u */    struct sockaddr_in address;  /* the libc network address data structure */    short int sock = -1;         /* file descriptor for the network socket */    if (argc != 3) {        fprintf(stderr, "Usage %s <port_num> <address>", argv[0]);        return EXIT_FAILURE;    }    address.sin_addr.s_addr = inet_addr(argv[2]); /* assign the address */    address.sin_port = htons(atoi(argv[2]));            /* translate int2port num */    sock = socket(AF_INET, SOCK_STREAM, 0);    if (connect(sock,(struct sockaddr *)&address,sizeof(address)) == 0) {        printf("%i is open\n", port);    }      close(sock);    return 0;}