如何从Web UI直接上传文件到s3？

I have a php code to upload file from my local system to AWS S3. and also I have php webpage which make user to upload a file and submit. now my requirement is I need to upload user uploaded file directly to AWS S3. Is there a way to upload file directly from UI to S3 without keeping it in system.? if there is a way how can I do that.

Thanks in advance.

Yes you can very much do that without keeping any system in between using sdk-for-javascript

You can refer to the sample web page that does exactly that.

Following is the code snippet from that page

function addPhoto(albumName) {
  var files = document.getElementById('photoupload').files;
  if (!files.length) {
    return alert('Please choose a file to upload first.');
  }
  var file = files[0];
  var fileName = file.name;
  var albumPhotosKey = encodeURIComponent(albumName) + '//';

  var photoKey = albumPhotosKey + fileName;
  s3.upload({
    Key: photoKey,
    Body: file,
    ACL: 'public-read'
  }, function(err, data) {
    if (err) {
      return alert('There was an error uploading your photo: ', err.message);
    }
    alert('Successfully uploaded photo.');
    viewAlbum(albumName);
  });
}

For setting your credentials to the SDK from browser scripts following are the ways in order of recommendation:

1. Using Amazon Cognito Identity to authenticate users and supply credentials
2. Using web federated identity
3. Hard coded in the script

More details about setting the credentials can be found here and here