Try with
/usr/bin/curl -v --header 'Host: dispflush' \
-H "CQ-Action: Delete" \
-H "CQ-Handle: /content/path/en" \
-H "CQ-Path: /content/path/en" \
-H "Content-Length: 0" \
-H "Content-Type: application/octet-stream" \
http://localhost:80/dispatcher/invalidate.cache
Arun Patidar