How to send file contents as body entity using cURL

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 </path/to/filename> as well as other variants with type info like --data </path/to/filename> --data-urlencode </path/to/filename> etc... the file is always attached. I need it as the body entity.

I believe you're looking for the @filename syntax, e.g.:

strip new lines

curl --data "@/path/to/filename" http://...

keep new lines

curl --data-binary "@/path/to/filename" http://...

curl will strip all newlines from the file. If you want to send the file with newlines intact, use --data-binary in place of --data

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