Unable to use variable in curl command

Question

I'm trying to use two variables in a curl command on my ksh program, but it doesn't work.

Example:

1. Original URL

   curl -s --header "Content-Type:application/json" --header "Accept:application/json" -X POST --data-binary '{"username":"foo","password":"foo_pwd"}' URL site
   

2. On my program

   user=foo
   pwd=foo_pwd
   curl -s --header "Content-Type:application/json" --header "Accept:application/json" -X POST --data-binary '{"username":"'"$user"'","password":"'"$pwd"'"}' URL site
   

I've tried also to escape double quote with backslash but it also doesn't work.

Answer 1

First examine your script

user=foo
pwd=foo_pwd
echo '{"username":"'"$user"'","password":"'"$pwd"'"}'

Then run

user=foo
pwd=foo_pwd
curl -s --header "Content-Type:application/json" --header "Accept:application/json" -X POST https://example.com --data-binary '{"username":"'"$user"'","password":"'"$pwd"'"}'