(SQL Server) Viewing the Raw HTTP Request Generated from a curl Command

See more CURL Examples

This example demonstrates how to convert a curl command into the exact raw HTTP request that would be sent to the server—without actually sending it.

By calling ToRawRequest, the curl command is translated into its underlying HTTP representation, including the request line, headers, and body. This is especially useful for debugging, verifying request formatting, and understanding how a curl command maps to a real HTTP request.

In this example, a POST request with a JSON body is constructed using curl syntax. The code then converts it to the raw HTTP request format and prints the result. This allows you to inspect details such as the Content-Length, header formatting, and the exact payload being transmitted.

This technique is helpful when troubleshooting issues related to request composition, encoding, or server-side behavior.

Note: This example requires Chilkat v11.5.0 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    -- Build a curl command and convert it to the raw HTTP request that would be sent.
    -- This allows you to inspect the exact request (headers + body) without actually sending it.

    --  curl -X POST https://httpbin.org/post \
    --       -H "Content-Type: application/json" \
    --       -d '{
    --             "title": "foo",
    --             "body": "bar",
    --             "userId": 1
    --           }'

    -- The backslashes at the end of lines are not required.  Chilkat ignores them if present.
    DECLARE @sbTargetCurl int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbTargetCurl OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @sbTargetCurl, 'AppendLn', @success OUT, ' curl -X POST https://httpbin.org/post \'
    EXEC sp_OAMethod @sbTargetCurl, 'AppendLn', @success OUT, '      -H "Content-Type: application/json" \'
    EXEC sp_OAMethod @sbTargetCurl, 'AppendLn', @success OUT, '      -d ''{'
    EXEC sp_OAMethod @sbTargetCurl, 'AppendLn', @success OUT, '            "title": "foo",'
    EXEC sp_OAMethod @sbTargetCurl, 'AppendLn', @success OUT, '            "body": "bar",'
    EXEC sp_OAMethod @sbTargetCurl, 'AppendLn', @success OUT, '            "userId": 1'
    EXEC sp_OAMethod @sbTargetCurl, 'AppendLn', @success OUT, '          }'''

    DECLARE @httpCurl int
    EXEC @hr = sp_OACreate 'Chilkat.HttpCurl', @httpCurl OUT

    -- Convert the curl command into a raw HTTP request string.
    -- This is useful for debugging, as it shows exactly what would be sent to the server
    -- (request line, headers, and body) for the given curl command.
    DECLARE @sbRawRequest int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbRawRequest OUT

    EXEC sp_OAMethod @sbTargetCurl, 'GetAsString', @sTmp0 OUT
    EXEC sp_OAMethod @httpCurl, 'ToRawRequest', @success OUT, @sTmp0, @sbRawRequest
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @httpCurl, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbTargetCurl
        EXEC @hr = sp_OADestroy @httpCurl
        EXEC @hr = sp_OADestroy @sbRawRequest
        RETURN
      END

    -- Display the generated raw HTTP request.
    EXEC sp_OAMethod @sbRawRequest, 'GetAsString', @sTmp0 OUT
    PRINT @sTmp0

    -- Expected output:

    -- POST /post HTTP/1.1
    -- Host: httpbin.org
    -- Content-Type: application/json
    -- Content-Length: 96
    -- 
    -- {
    --             "title": "foo",
    --             "body": "bar",
    --             "userId": 1
    --           }

    EXEC @hr = sp_OADestroy @sbTargetCurl
    EXEC @hr = sp_OADestroy @httpCurl
    EXEC @hr = sp_OADestroy @sbRawRequest


END
GO