PHP ftp_cdup() 函数

PHP ftp_cdup() 函数用于将当前目录更改为 FTP 服务器上的父目录。

语法

ftp_cdup(ftp) 

参数

返回值

成功时返回 true，失败时返回 false。

示例:

下面的示例显示了ftp_cdup()函数的用法。

<?php
//要使用的FTP服务器
$ftp_server = "ftp.example.com";

//FTP 连接的用户名
$ftp_user = "user";
  
//用户密码
$ftp_pass = "password";
   
//建立连接或者连接失败
$ftp = ftp_connect($ftp_server)
    or die("Could not connect to $ftp_server");
   
if($ftp) {
  echo "Successfully connected to $ftp_server!\n";
 
  //尝试登录
  if(@ftp_login($ftp, $ftp_user, $ftp_pass)) {
    echo "Connected as $ftp_user@$ftp_server\n";

    //将当前目录更改为public_html
    ftp_chdir($ftp, "public_html");

    //显示当前目录
    echo "Current directory: ".ftp_pwd($ftp)."\n"; 

    //返回上级目录
    if (ftp_cdup($ftp)) { 
      echo "cdup successful\n";
    } else {
      echo "cdup not successful\n";
    }

    //显示当前目录
    echo "Current directory: ".ftp_pwd($ftp)."\n"; 
    
  } else {
    echo "Couldn't connect as $ftp_user\n";
  }
 
  //关闭连接
  if(ftp_close($ftp)) {
    echo "Connection closed successfully!\n"; 
  } 
}
?> 

上述代码的输出将是:

Successfully connected to ftp.example.com!
Connected as user@ftp.example.com
Current directory: /public_html
cdup successful
Current directory: /
Connection closed successfully!