无法连接到本地主机

Question

我正在运行linux mint，并在命令终端中输入了一些命令来连接到本地主机，但它一直说连接失败。

这是我键入：

echo "echo test" | ./<my executable> localhost <port #> 

这里是我的连接代码：

int r = connect(sock, addrList->ai_addr, addrList->ai_addrlen); 
    if (r < 0) { 
    printf("Connection failed\n"); 
    exit(1); 
    } 

这里是全码：

int main(int argc, char *argv[]) { 
    if (argc != 3) { 
    printf("Invalid arguments\n"); 
    exit(1); 
    } 

    char *serverIP = argv[1]; /*Server hostname*/ 
    char *portNumber = argv[2]; /*Port Number*/ 
    void *numericAddress; 
    char addrBuffer[INET6_ADDRSTRLEN]; 
    in_port_t port; 
    char buffer_stdin[65535]; 
    char buffer_stdout[65535]; 
    int bytes_read = 0; 
    int bytes_written = 0; 

    /*getting integral number of string representation of port number*/ 
    in_port_t servPort = atoi(argv[2]); 

    /*------------------get binary number of hostname-----------------*/ 
    struct addrinfo addrCriteria; 
    memset(&addrCriteria, 0, sizeof(addrCriteria)); 
    addrCriteria.ai_family = AF_INET; 
    addrCriteria.ai_socktype = SOCK_STREAM; 
    addrCriteria.ai_protocol = IPPROTO_TCP; 

    struct addrinfo *addrList; 

    int rtnVal = getaddrinfo(serverIP, portNumber, &addrCriteria, &addrList); 
    if (rtnVal != 0) { 
    printf("getaddrinfo() failed\n"); 
    exit(1); 
    } 

    numericAddress = &((struct sockaddr_in *) (addrList->ai_addr))->sin_addr; 
    /*Converting port to binary*/ 
    ((struct sockaddr_in *)(addrList->ai_addr))->sin_port = htons(servPort); 
    /*----------------------------------------------------------------*/ 

    inet_ntop(addrList->ai_addr->sa_family, numericAddress, addrBuffer, sizeof(addrBuffer)); 
    printf("IP ADDRESS: %s\n", addrBuffer); 

    /*Creating socket*/ 
    int sock = socket(AF_INET,SOCK_STREAM, IPPROTO_TCP); 
    if (sock < 0) { 
    printf("error creating socket\n"); 
    exit(1); 
    } 

    /*Establish connection to the echo server*/ 
    int r = connect(sock, addrList->ai_addr, addrList->ai_addrlen); 
    if (r < 0) { 
    perror("Connection failed\n"); 
    exit(1); 
    } 

    /*Reading from stdin and writing to socket until stdin ends 
    bytes_read = read(0, buffer_stdin, sizeof(buffer_stdin)); 
    write(sock, buffer_stdin, bytes_read);*/ 

    while ((bytes_read = read(0, buffer_stdin, sizeof(buffer_stdin)-1)) > 0) { 
    write(sock, buffer_stdin, bytes_read); 
    } 

    /*Shutting down write end of socket*/ 
    int r_shutdown = shutdown(sock, SHUT_WR); 
    if (r_shutdown < 0) { 
    printf("Shutting down write end of socket failed\n"); 
    exit(1); 
    } 

    /*Reading from socket and writing to stdout until socket ends*/ 
    while ((bytes_read = read(sock, buffer_stdout, sizeof(buffer_stdout)-1)) > 0) { 
    write(1, buffer_stdout, bytes_read); 
    } 

    close(sock); 
    exit(0); 
} 

我是否需要安装东西连接到本地主机？

感谢

编辑：确定这里是一个更新：

首先我键入指令终端的：chmod a + X exe文件（其中EXE是我们的UDP服务器） 然后我输入：./ exe例如./exe 2525 然后我输入：echo“echo test”| ./ localhost

但是，如果发生这种情况，终端不会返回“回声测试”，就像它正在等待用户输入，或者如果它陷入无限循环一样。

Answer 1

它看起来像您需要提供在命令行上的本地主机：

./exe localhost 2525 

或：

echo test | ./exe localhost 2525