FAQ: 4.20 curl doesn't return error for HTTP non-200 responses

  4.17 Non-functional connect timeouts on Windows

  4.18 file:// URLs containing drive letters (Windows, NetWare)

  4.19 Why doesn't cURL return an error when the network cable is unplugged?

  4.20 curl doesn't return error for HTTP non-200 responses!

 5. libcurl Issues

  5.1 Is libcurl thread-safe?

  by having the application monitor the network connection on its own using an

  OS-specific mechanism, then signalling libcurl to abort (see also item 5.13).

  4.20 curl doesn't return error for HTTP non-200 responses!

  Correct. Unless you use -f (--fail).

  When doing HTTP transfers, curl will perform exactly what you're asking it

  to do and if successful it will not return an error. You can use curl to

  test your web server's "file not found" page (that gets 404 back), you can

  use it to check your authentication protected web pages (that get a 401

  back) and so on.

  The specific HTTP response code does not constitute a problem or error for

  curl. It simply sends and delivers HTTP as you asked and if that worked,

  everything is fine and dandy. The response code is generally providing more

  higher level error information that curl doesn't care about. The error was

  not in the HTTP transfer.

  If you want your command line to treat error codes in the 400 and up range

  as errors and thus return a non-zero value and possibly show an error

  message, curl has a dedicated option for that: -f (CURLOPT_FAILONERROR in

  libcurl speak).

5. libcurl Issues