PHP如何使用ftp_alloc()函数？代码实例

ftp_alloc()函数是PHP中的内置函数, 用于为要在FTP服务器中上传的文件分配空间。

语法如下：

ftp_alloc( $ftp_connection, $filesize, $result );

参数：此函数接受上述和以下描述的三个参数：

• $ ftp_connection：它是必填参数。它指定用于分配空间和上载文件的现有FTP连接。
• $ filesize：它是必填参数。它以字节为单位指定文件的大小, 即要分配的字节数。
• $result：此参数是可选的。它指定一个变量来存储响应。

返回值：成功返回True, 失败返回False。

注意：

• 此功能可用于PHP 5.0.0和更高版本。
• 以下示例无法在在线IDE上运行。因此, 请尝试使用适当的ftp服务器名称在某些PHP托管服务器或localhost中运行。

以下示例说明了PHP中的ftp_alloc()函数：

范例1：

<?php
  
// Connect to FTP server
  
// Use a correct ftp server 
$ftp_server = "localhost" ;
  
// Use correct ftp username
$ftp_username = "user" ;
  
// Use correct ftp password corresponding
// to the ftp username
$ftp_userpass = "user" ;
  
// File name or path to upload to ftp server
$file = "filetoupload.txt" ;
   
// Establishing ftp connection 
$ftp_connection = ftp_connect( $ftp_server ) 
     or die ( "Could not connect to $ftp_server" );
  
if ( $ftp_connection ) {
     echo "successfully connected to the ftp server!" ;
      
     // Logging in to established connection
     // with ftp username password
     $login = ftp_login( $ftp_connection , $ftp_username , $ftp_userpass );
      
     if ( $login ) {
          
         // Checking whether logged in successfully or not
         echo "<br>logged in successfully!" ;
          
         // Allocating space for the file as specified
         // i.e. in $file
         if (ftp_alloc( $ftp_connection , filesize ( $file ), $result )) {
             echo "<br>space successfully allocated on the FTP server" ;
              
             if (ftp_put( $ftp_connection , "uploadedfile_name_in_server.txt" , $file , FTP_ASCII)) {
                 echo "<br>Uploaded successful $file." ;
             }
             else {
                  echo "<br>Error while uploading $file." ;
             }
         }
         else {
             echo "<br>space allocation failed!" ;   
         }
     }
     else {
         echo "<br>login failed!" ;
     }
  
     // Closeing  connection
     if (ftp_close( $ftp_connection )) {
         echo "<br>Connection closed Successfully!" ;
     } 
}
  
?>

输出如下：

successfully connected to the ftp server!
logged in successfully!
space successfully allocated on the FTP server
Uploaded successful filetoupload.txt.
Connection closed Successfully!

范例2：使用端口号21连接到ftp服务器, 然后分配和上传文件。

<?php
  
// Connect to FTP server
  
// Use a correct ftp server 
$ftp_server = "localhost" ;
  
// Use correct ftp username
$ftp_username = "user" ;
  
// Use correct ftp password corresponding
// to the ftp username
$ftp_userpass = "user" ;
  
// File name or path to upload to ftp server
$file = "filetoupload.txt" ;
   
// Establishing ftp connection 
$ftp_connection = ftp_connect( $ftp_server , 21) 
     or die ( "Could not connect to $ftp_server" );
  
if ( $ftp_connection ) {
     echo "successfully connected to the ftp server!" ;
      
     // Logging in to established connection
     // with ftp username password
     $login = ftp_login( $ftp_connection , $ftp_username , $ftp_userpass );
      
     if ( $login ) {
          
         // Checking whether logged in successfully or not
         echo "<br>logged in successfully!" ;
          
         // Allocating space for the file as specified
         // i.e. in $file
         if (ftp_alloc( $ftp_connection , filesize ( $file ), $result )) {
             echo "<br>space successfully allocated on the FTP server" ;
              
             if (ftp_put( $ftp_connection , "uploadedfile_name_in_server.txt" , $file , FTP_ASCII)) {
                 echo "<br>Uploaded successful $file." ;
             }
             else {
                  echo "<br>Error while uploading $file." ;
             }
         }
         else {
             echo "<br>space allocation failed!" ;   
         }
     }
     else {
         echo "<br>login failed!" ;
     }
  
     // Closeing  connection
     if (ftp_close( $ftp_connection )) {
         echo "<br>Connection closed Successfully!" ;
     } 
}
  
?>

输出如下：

successfully connected to the ftp server!
logged in successfully!
space successfully allocated on the FTP server
Uploaded successful filetoupload.txt.
Connection closed Successfully!

参考： https://www.php.net/manual/en/function.ftp-alloc.php

---