I was having a little trouble with the SmugMug upload API, and they needed a raw dump of the request to help debug it. I downloaded Wireshark, but it didn’t work out of the box (it doesn’t see any interfaces, which is a common issue that I’m sure is easy to fix). So I did a couple google searches, and found there’s a built-in tool called tcpdump. From the Terminal:
sudo tcpdump -s 0 -A -i en0 host upload.smugmug.com
That’s all I needed to do to get my raw HTTP POST dump. Just thought y’all might want to know that.