curl post json

curl -X POST -H "Content-Type: application/json" \
 -d '{"username":"abc","password":"abc"}' \
 https://api.example.com/v2/login

$ch = curl_init( $url );
# Setup request to send json via POST.
$payload = json_encode( array( "customer"=> $data ) );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $payload );
curl_setopt( $ch, CURLOPT_HTTPHEADER, array('Content-Type:application/json'));
# Return response instead of printing.
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
# Send request.
$result = curl_exec($ch);
curl_close($ch);

curl -X POST -H "Content-Type: application/json" -d @../data/cats.json http://localhost:8080/mSfvMwNAfj

curl -H "Accept: application/json" -H "Content-type: application/json" -X POST -d '{"id":100}' http://localhost/api/postJsonReader.do

curl -X POST -H "Content-Type: text/plain" --data "this is raw data" http://78.41.xx.xx:7778/