Stress testing a file-upload with Apache Bench

gistfile1.txt

$ab -n 10 -c 2 -p /Users/post_file.txt -T "multipart/form-data; boundary=1234567890" http://localhost/upload

post_file.txt (use CRLF line-endings):

--1234567890
Content-Disposition: form-data; filename="file.png"
Content-Type: application/octet-stream
Content-Transfer-Encoding: binary

<base64 encoded file>
--1234567890--