How to send file contents as body entity using cURL

Question

I am using cURL command line utility to send HTTP POST to a web service. I want to include a file\'s contents as the body entity of the POST. I have tried using -d &

Answer 1

I know the question has been answered, but in my case I was trying to send the content of a text file to the Slack Webhook api and for some reason the above answer did not work. Anywho, this is what finally did the trick for me:

curl -X POST -H --silent --data-urlencode "payload={\"text\": \"$(cat file.txt | sed "s/\"/'/g")\"}" https://hooks.slack.com/services/XXX