如何在CURL下载文件时使用CURLOPT_WRITEFUNCTION

Question

My Class for download file direct from a link:

MyClass{

          function download($link){
                ......
                $ch = curl_init($link);
                curl_setopt($ch, CURLOPT_FILE, $File->handle);
                curl_setopt($ch,CURLOPT_WRITEFUNCTION , array($this,'__writeFunction'));
                curl_exec($ch);
                curl_close($ch);
                $File->close();
                ......

            }

          function __writeFunction($curl, $data) {
                return strlen($data);            
          } 
}

I want know how to use CRULOPT_WRITEFUNCTION when download file. Above code if i remove line:

curl_setopt($ch,CURLOPT_WRITEFUNCTION , array($this,'__writeFunction'));

Then it will run good, i can download that file.But if i use CURL_WRITEFUNCTION option i can't download file.

Answer 1

Why do you use curl to download a file? Is there a special reason? You can simply use fopen and fread

I have written a small class for it.

<?php
class Utils_FileDownload  {
    private $source;
    private $dest;
    private $buffer;
    private $overwrite;
    public function __construct($source,$dest,$buffer=4096,$overwrite=false){
        $this->source = $source;
        $this->dest   = $dest;
        $this->buffer = $buffer; 
        $this->overwrite = $overwrite;
    }
    public function download(){
        if($this->overwrite||!file_exists($this->dest)){
            if(!is_dir(dirname($this->dest))){mkdir(dirname($this->dest),0755,true);}
            if($this->source==""){
                $resource = false;
                Utils_Logging_Logger::getLogger()->log("source must not be empty.",Utils_Logging_Logger::TYPE_ERROR);
            }
            else{ $resource = fopen($this->source,"rb"); }
            if($this->source==""){
                $dest = false;
                Utils_Logging_Logger::getLogger()->log("destination must not be empty.",Utils_Logging_Logger::TYPE_ERROR);
            }
            else{ $dest     = fopen($this->dest,"wb"); }
            if($resource!==false&&$dest!==false){
                while(!feof($resource)){
                    $read = fread($resource,$this->buffer);
                    fwrite($dest,$read,$this->buffer);
                }
                chmod($this->dest,0644);
                fclose($dest); fclose($resource);
                return true;
            }else{
                 return false;   
            }
        }else{
            return false;
        }
    }
}