(Unicode C++) curl with Variable Substitution in the Request Body

See more CURL Examples

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

Chilkat C/C++ Library Downloads
MS Visual C/C++ C++ Builder Linux C/C++ Alpine Linux C/C++	MacOS C/C++ iOS C/C++ Android C/C++ MinGW C/C++

#include <CkStringBuilderW.h>
#include <CkHttpCurlW.h>

void ChilkatSample(void)
    {
    bool success = false;

    // Variables can also be used within the HTTP request body.
    // Variable names are enclosed between {{ and }}

    // Here is a curl command with two variables {{name}} and {{age}} located in the data.

    // curl -X POST https://api.example.com/data \
    //   -H "Content-Type: application/json" \
    //   -d '{"name":"{{name}}","age":{{age}}}'

    CkStringBuilderW sbCurl;
    sbCurl.AppendLn(L"curl -X POST https://api.example.com/data \\");
    sbCurl.AppendLn(L"  -H \"Content-Type: application/json\" \\");
    sbCurl.AppendLn(L"  -d '{\"name\":\"{{name}}\",\"age\":{{age}}}'");

    CkHttpCurlW curl;

    // Provide values for variables.
    curl.SetVar(L"name",L"Alice");
    curl.SetVar(L"age",L"30");

    // To demonstrate how the variables are replaced, this example does not execute the curl command. 
    // Instead, it generates the raw HTTP request that would be sent if the curl command were run.
    CkStringBuilderW sbRawRequest;
    success = curl.ToRawRequest(sbCurl.getAsString(),sbRawRequest);
    if (success == false) {
        wprintf(L"%s\n",curl.lastErrorText());
        return;
    }

    wprintf(L"%s\n",sbRawRequest.getAsString());

    // Output:

    // POST /data HTTP/1.1
    // Host: api.example.com
    // Content-Type: application/json
    // Content-Length: 25
    // 
    // {"name":"Alice","age":30}

    // --------------------------------------------------------------------------------------------------
    // Note: Variable substitution in the request body can be turned off by 
    // setting the EnableBodyVars property equal to false

    curl.put_EnableBodyVars(false);

    success = curl.ToRawRequest(sbCurl.getAsString(),sbRawRequest);
    if (success == false) {
        wprintf(L"%s\n",curl.lastErrorText());
        return;
    }

    wprintf(L"%s\n",sbRawRequest.getAsString());

    // The raw request with body variable substitution disable:

    // Host: api.example.com
    // Content-Type: application/json
    // Content-Length: 33
    // 
    // {"name":"{{name}}","age":{{age}}}
    }