The uploaded file has some strange content ？

[anjisZhou]

This is my upload code, uploaded to Amazon's server via http auto r = cpr::Put(url, cpr::Multipart{{"file", cpr::File{_filePath}}}, cpr::ProgressCallback([&](size_t downloadTotal, size_t downloadNow, size_t uploadTotal, size_t uploadNow) -> bool { return true; })); Why does the file I upload to the server have these contents?

[COM8]

This looks rather interesting and should not be there :D What software do you use at the receiver end, since I'm not able to reproduce this. What version of CPR are you using? What platform are you on (Windows, Linux, ...)?

[anjisZhou]

I am using Amazon's file server and I don't know it very well. It feels that it does not support "boundary", I just used this method to upload successfully

auto r = cpr::Put(url, cpr::Body(fileData.data(),fileData.size()), cpr::Header{{"content-type","application/octet-stream"}});

[COM8]

I'm currently unable to reproduce this issue. I'm using the following test case:

TEST(FileUpload, FormPostSingleTest) {
    Url url{"http://httpbin.org/put"};
    Response response = cpr::Put(url, Multipart{{"someFile", cpr::File{"/home/fabian/test.txt"}}});
    std::cout << response.text;
    EXPECT_EQ(url, response.url);
    EXPECT_EQ(200, response.status_code);
    EXPECT_EQ(ErrorCode::OK, response.error.code);
}

Which then results in the following with the correct file content.

{
  "args": {}, 
  "data": "", 
  "files": {
    "someFile": "Hello!\n"
  }, 
  "form": {}, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "deflate, gzip", 
    "Content-Length": "197", 
    "Content-Type": "multipart/form-data; boundary=------------------------849ce773b180b64b", 
    "Host": "httpbin.org", 
    "User-Agent": "curl/7.75.0", 
    "X-Amzn-Trace-Id": "Root=1-60fea159-797b814b42c9fb3d3c11d650"
  }, 
  "json": null, 
  "origin": "131.159.24.141", 
  "url": "http://httpbin.org/put"
}

[COM8]

Can anyone provide me with a small example project, so I can reproduce this error?

[lsaejn]

yes, i met this before, i got strange content at the beginning and end of the file-content:

--------------------------9add7af2b74072ba Content-Disposition: form-data; name="someFile"; filename="main.cpp" Content-Type: application/octet-stream

#include <iostream>

#pragma comment(lib, "libcurl-d.lib")

#include <cpr/cpr.h>
#include <fstream>

int main(int argc, char* args[])
{
    {
        //cpr::Url url{ "http://httpbin.org/put" };
        cpr::Url url{ "http://localhost/testFile.cpp" };
        cpr::Response response = cpr::Put(url, cpr::Multipart{
            {"someFile", cpr::File{"./main.cpp"}} });
        std::cout << response.text;
        getchar();
    }
}

--------------------------9add7af2b74072ba--

[lsaejn]

Can anyone provide me with a small example project, so I can reproduce this error?

i'm using nginx-1.12.2, windows. i modify nginx.conf to support PUT method by adding the following contents:

 dav_methods  PUT;

[caiomcg]

Any updates on this? I am uploading wave files to GCP and the contents of the file have information on multipart. Therefore, we have failures while reproducing waves.

Edit:

More context:

• LibCPR version: 1.10.0
• OS: Mac OS Ventura 13.2

[caiomcg]

Any updates on this? I am uploading wave files to GCP and the contents of the file have information on multipart. Therefore, we have failures while reproducing waves.

Edit:

More context:

• LibCPR version: 1.10.0
• OS: Mac OS Ventura 13.2

Upon a quick investigation I have concluded that LibCPR is doing the correct approach, the problem relies within GCS as it doesn't handle Multipart. I changed my approach to send the entire file in the body of my request.

Reference:

• https://stackoverflow.com/questions/57750518/why-do-files-uploaded-with-curl-contain-part-of-the-request-header-like-bounda

[COM8]

@caiomcg thanks for looking into this and providing a ref. solution. Does this mean, we need to change anything on the cpr side of things since as far as I can see it, it's a server side issue and therefore not something we can fix?