Using cURL to upload POST data with files

You need to use the -F option:
-F/--form <name=content> Specify HTTP multipart POST data (H)

Try this:

curl \
  -F "userid=1" \
  -F "filecomment=This is an image file" \
  -F "image=@/home/user1/Desktop/test.jpg" \
  localhost/uploader.php

Catching the user id as path variable (recommended):

curl -i -X POST -H "Content-Type: multipart/form-data" 
-F "data=@test.mp3" http://mysuperserver/media/1234/upload/

Catching the user id as part of the form:

curl -i -X POST -H "Content-Type: multipart/form-data" 
-F "data=@test.mp3;userid=1234" http://mysuperserver/media/upload/

or:

curl -i -X POST -H "Content-Type: multipart/form-data" 
-F "data=@test.mp3" -F "userid=1234" http://mysuperserver/media/upload/

Here is my solution, I have been reading a lot of posts and they were really helpful. Finally I wrote some code for small files, with cURL and PHP that I think its really useful.

public function postFile()
{    
        $file_url = "test.txt";  //here is the file route, in this case is on same directory but you can set URL too like "http://examplewebsite.com/test.txt"
        $eol = "\r\n"; //default line-break for mime type
        $BOUNDARY = md5(time()); //random boundaryid, is a separator for each param on my post curl function
        $BODY=""; //init my curl body
        $BODY.= '--'.$BOUNDARY. $eol; //start param header
        $BODY .= 'Content-Disposition: form-data; name="sometext"' . $eol . $eol; // last Content with 2 $eol, in this case is only 1 content.
        $BODY .= "Some Data" . $eol;//param data in this case is a simple post data and 1 $eol for the end of the data
        $BODY.= '--'.$BOUNDARY. $eol; // start 2nd param,
        $BODY.= 'Content-Disposition: form-data; name="somefile"; filename="test.txt"'. $eol ; //first Content data for post file, remember you only put 1 when you are going to add more Contents, and 2 on the last, to close the Content Instance
        $BODY.= 'Content-Type: application/octet-stream' . $eol; //Same before row
        $BODY.= 'Content-Transfer-Encoding: base64' . $eol . $eol; // we put the last Content and 2 $eol,
        $BODY.= chunk_split(base64_encode(file_get_contents($file_url))) . $eol; // we write the Base64 File Content and the $eol to finish the data,
        $BODY.= '--'.$BOUNDARY .'--' . $eol. $eol; // we close the param and the post width "--" and 2 $eol at the end of our boundary header.



        $ch = curl_init(); //init curl
        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
                         'X_PARAM_TOKEN : 71e2cb8b-42b7-4bf0-b2e8-53fbd2f578f9' //custom header for my api validation you can get it from $_SERVER["HTTP_X_PARAM_TOKEN"] variable
                         ,"Content-Type: multipart/form-data; boundary=".$BOUNDARY) //setting our mime type for make it work on $_FILE variable
                    );
        curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/1.0 (Windows NT 6.1; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0'); //setting our user agent
        curl_setopt($ch, CURLOPT_URL, "api.endpoint.post"); //setting our api post url
        curl_setopt($ch, CURLOPT_COOKIEJAR, $BOUNDARY.'.txt'); //saving cookies just in case we want
        curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1); // call return content
        curl_setopt ($ch, CURLOPT_FOLLOWLOCATION, 1); navigate the endpoint
        curl_setopt($ch, CURLOPT_POST, true); //set as post
        curl_setopt($ch, CURLOPT_POSTFIELDS, $BODY); // set our $BODY 


        $response = curl_exec($ch); // start curl navigation

     print_r($response); //print response

}

With this we should be get on the "api.endpoint.post" the following vars posted. You can easily test with this script, and you should be receive this debugs on the function postFile() at the last row.

print_r($response); //print response

public function getPostFile()
{

    echo "\n\n_SERVER\n";
    echo "<pre>";
    print_r($_SERVER['HTTP_X_PARAM_TOKEN']);
    echo "/<pre>";
    echo "_POST\n";
    echo "<pre>";
    print_r($_POST['sometext']);
    echo "/<pre>";
    echo "_FILES\n";
    echo "<pre>";
    print_r($_FILEST['somefile']);
    echo "/<pre>";
}

It should work well, they may be better solutions but this works and is really helpful to understand how the Boundary and multipart/from-data mime works on PHP and cURL library.

if you are uploading binary file such as csv, use below format to upload file

curl -X POST \
    'http://localhost:8080/workers' \
    -H 'authorization: eyJhbGciOiJIUzI1NiIsInR5cCI6ImFjY2VzcyIsInR5cGUiOiJhY2Nlc3MifQ.eyJ1c2VySWQiOjEsImFjY291bnRJZCI6MSwiaWF0IjoxNTExMzMwMzg5LCJleHAiOjE1MTM5MjIzODksImF1ZCI6Imh0dHBzOi8veW91cmRvbWFpbi5jb20iLCJpc3MiOiJmZWF0aGVycyIsInN1YiI6ImFub255bW91cyJ9.HWk7qJ0uK6SEi8qSeeB6-TGslDlZOTpG51U6kVi8nYc' \
    -H 'content-type: application/x-www-form-urlencoded' \
    --data-binary '@/home/limitless/Downloads/iRoute Masters - Workers.csv'

After a lot of tries this command worked for me:

curl -v -F filename=image.jpg -F upload=@image.jpg http://localhost:8080/api/upload

The issue that lead me here turned out to be a basic user error - I wasn't including the @ sign in the path of the file and so curl was posting the path/name of the file rather than the contents. The Content-Length value was therefore 8 rather than the 479 I expected to see given the legnth of my test file.

The Content-Length header will be automatically calculated when curl reads and posts the file.

curl -i -H "Content-Type: application/xml" --data "@test.xml" -v -X POST https://<url>/<uri/

... < Content-Length: 479 ...

Posting this here to assist other newbies in future.

As an alternative to curl, you can use HTTPie, it'a CLI, cURL-like tool for humans.

Installation instructions: https://github.com/jakubroztocil/httpie#installation Then, run: http -f POST http://localhost:4040/api/users username=johnsnow photo@images/avatar.jpg HTTP/1.1 200 OK Access-Control-Expose-Headers: X-Frontend Cache-control: no-store Connection: keep-alive Content-Encoding: gzip Content-Length: 89 Content-Type: text/html; charset=windows-1251 Date: Tue, 26 Jun 2018 11:11:55 GMT Pragma: no-cache Server: Apache Vary: Accept-Encoding X-Frontend: front623311 ...

I got it worked with this command curl -F 'filename=@/home/yourhomedirextory/file.txt' http://yourserver/upload

cat test.txt 

file test.txt content.

curl -v -F "hello=word" -F "file=@test.txt" https://httpbin.org/post

> POST /post HTTP/2
> Host: httpbin.org
> user-agent: curl/7.68.0
> accept: */*
> content-length: 307
> content-type: multipart/form-data; boundary=------------------------78a9f655d8c87a53
> 
* Connection state changed (MAX_CONCURRENT_STREAMS == 128)!
* We are completely uploaded and fine
< HTTP/2 200 
< date: Mon, 15 Nov 2021 06:18:47 GMT
< content-type: application/json
< content-length: 510
< server: gunicorn/19.9.0
< access-control-allow-origin: *
< access-control-allow-credentials: true
< 
{
  "args": {}, 
  "data": "", 
  "files": {
    "file": "file test.txt content.\n"
  }, 
  "form": {
    "hello": "word"
  }, 
  "headers": {
    "Accept": "*/*", 
    "Content-Length": "307", 
    "Content-Type": "multipart/form-data; boundary=------------------------78a9f655d8c87a53", 
    "Host": "httpbin.org", 
    "User-Agent": "curl/7.68.0", 
    "X-Amzn-Trace-Id": "Root=1-6191fbc7-6c68fead194d943d07148860"
  }, 
  "json": null, 
  "origin": "43.129.xx.xxx", 
  "url": "https://httpbin.org/post"
}

Here is how to correctly escape arbitrary filenames of uploaded files with bash:

#!/bin/bash
set -eu

f="$1"
f=${f//\\/\\\\}
f=${f//\"/\\\"}
f=${f//;/\\;}

curl --silent --form "uploaded=@\"$f\"" "$2"

save all sent files to folder: php file on host. u.php:

<?php
$uploaddir = 'C:/VALID_DIR/';
 echo '<pre>';
foreach ($_FILES as $key => $file) {
    if(!isset($file) || !isset($file['name'])) continue;
    $uploadfile = $uploaddir . basename($file['name']);
   
    if (move_uploaded_file($file['tmp_name'], $uploadfile)) {
        echo "$key file > $uploadfile .\n";
    } else {
        echo " Error $key  file.\n";
    }
}
print_r($_FILES);
print "</pre>";?>

Usage from client:

curl -v -F filename=ff.xml -F upload=@ff.xml https://myhost.com/u.php

This is worked for me.

My VM crashed it has only internet connection. I recovered some files this way.