PHP CURL File Download – A Simple Example

Welcome to a tutorial on how to download files with PHP CURL. Need to fetch a file from another server with PHP CURL? Yes, it is possible.

That should cover the basics, but let us walk through a few more examples in this guide – Read on!

ⓘ I have included a zip file with all the source code at the start of this tutorial, so you don’t have to copy-paste everything… Or if you just want to dive straight in.

 

 

REAL QUICK SLIDES

 

TABLE OF CONTENTS

Download & Notes	CURL Download	Useful Bits & Links
The End

 

 

EXAMPLE CODE DOWNLOAD

Click here to download all the example source code, I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

 

QUICK NOTES

If you spot a bug, please feel free to comment below. I try to answer questions too, but it is one person versus the entire world… If you need answers urgently, please check out my list of websites to get help with programming.

 

 

 

USING CURL TO DOWNLOAD FILES

<?php
// (A) SETTINGS
set_time_limit(0); // No script timeout, if expecting large download
$source = "http://localhost/README.txt"; // Target file to download
$destination = "saved.txt"; // Save to this file
$timeout = 30; // 30 seconds CURL timeout, increase if downloading large file

// (B) FILE HANDLER
$fh = fopen($destination, "w") or die("ERROR opening " . $destination);

// (C) CURL INIT
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $source);
curl_setopt($ch, CURLOPT_FILE, $fh);
curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);

// (D) CURL RUN
curl_exec($ch);
if (curl_errno($ch)) {
  // (D1) CURL ERROR
  echo "CURL ERROR - " . curl_error($ch);
} else {
  // (D2) CURL OK
  // NOTE: HTTP STATUS CODE 200 = OK
  // BAD DOWNLOAD IF SERVER RETURNS 401 (UNAUTHORIZED), 403 (FORBIDDEN), 404 (NOT FOUND)
  $status = curl_getinfo($ch);
  // print_r($status);
  echo $status['http_code'] == 200 ? "OK" : "ERROR - " . $status['http_code'] ;
}

// (D3) CLOSE CURL & FILE
curl_close($ch);
fclose($fh);

Yes, this is practically just an “improved version” of the introduction snippet.

• A – A bunch of settings, where to download the file from, where to save it to.
• B – Creating a file on the local server.
• C – The CURL request itself.
• D – Error handling and what to do after the download.

 

 

DOWNLOADING LARGE FILES

<?php
// (A) SETTINGS
set_time_limit(0);
$source = "http://localhost/README.txt";
$destination = "saved.txt";
$block = 4096; // Read 4096 bytes per block to prevent memory

// (B) FILE HANDLERS
$sh = fopen($source, 'rb') or die("ERROR opening $source");
$dh = fopen($destination, 'w') or die("ERROR opening $destination");

// (C) DOWNLOAD, BLOCK-BY-BLOCK
while (!feof($sh)) {
  if (fwrite($dh, fread($sh, $block)) === false) { echo "FWRITE ERROR."; }
  flush();
}

// (D) DONE!
echo "DONE.";
fclose($sh);
fclose($dh);

If you are dealing with very large files, I will recommend dropping CURL and just use fopen-fwrite-fread instead – We can limit the number of bytes fread() can read at once, to prevent an “out-of-memory” error.

 

SUPER SIMPLE DOWNLOAD

<?php
$source = "http://localhost/README.txt";
$destination = "saved.txt";
file_put_contents($destination, file_get_contents($source));
echo "OK";

For you guys who just want a real simple file download… We don’t actually even need CURL. Just file_put_contents() and file_get_contents().

 

 

 

INFOGRAPHIC CHEAT SHEET

 

LINKS & REFERENCES

• CURL – PHP
• fopen – PHP
• How To Write & Append To Files In PHP – Code Boxx