Lets say I have a large file that I want to HTTP POST to a webservice using PHP and curl. The file is larger than the amount of memory I can let PHP use.
Basically I'm looking for a way to stream the content of a file directly to curl, without reading the entire file into memory.
I have success using multipart POSTs and PUT, but not "binary data" upload with POST.
What I want to achieve in PHP is what this command line does:
$ curl -X POST -H "Content-Type: image/jpeg" \
--data-binary "@large.jpg" "http://example.com/myservice"
Tried a lot of options with curl_setopt, such as INFILE, POSTFIELDS, Content-Type header, but no luck.
It works with multipart though, but I need a raw POST request, no multiparts:
$post['file'] = "@large.jpg";
curl_setopt($c, CURLOPT_POSTFIELDS, $post);
The PHP/CURL binding supports the CURLOPT_READFUNCTION option, which allows you to pass data to send chunk-by-chunk using that callback.
Pretty much exactly the same logic as is shown in this C example: http://curl.haxx.se/libcurl/c/post-callback.html
来源：https://stackoverflow.com/questions/5260985/how-to-upload-a-file-with-php-curl-and-http-post-by-streaming-the-file