Command line concepts
curl started out as a command-line tool and it has been invoked from shellprompts and from within scripts by countless users over the years.
Garbage in gives garbage out
curl has little will of its own. It tries to please you and your wishes to alarge extent. It also means that it tries to play with what you give it. Ifyou misspell an option, it might do something unintended. If you pass in aslightly illegal URL, chances are curl still deals with it and proceeds. Itmeans that you can pass in crazy data in some options and you can have curlpass on that crazy data in its transfer operation.
This is a design choice, as it allows you to really tweak how curl does itsprotocol communications and you can have curl massage your serverimplementations in the most creative ways.