License your first application

Now that you have defined a license policy, you need a license template to integrate LM-X with your application.

License file

To generate an XML license template:

Create a template of the license you are interested in.
Run the license generator provided with LM-X, xmllicgen, as described in Generating licenses.

In the following example we assume the license will expire on January 1, 2018. This license defines one feature with version 1.0.

<?xml version="1.0" encoding="UTF-8"?>
<LICENSEFILE>
  <FEATURE NAME="feature">
    <SETTING MAJOR_VERSION="1"/>
    <SETTING MINOR_VERSION="0"/>
    <SETTING END="2018-01-01"/>
  </FEATURE>
</LICENSEFILE>

To convert the above LM-X license template to a license file, run xmlicgen as shown below.

On Unix:

# xmllicgen license.xml

On Windows:

# xmllicgen.exe license.xml

The resulting file will be license.lic. Xmllicgen will automatically replace your ".xml" extension with ".lic" and save the license next to your template.

Source code

Header file

First of all, you must include the required header, lmx.h, located in the include directory of your SDK.

#include "lmx.h"

If your project and LM-X SDK are in separate directories, remember to specify the include directory for your compiler. For example:

GCC:

gcc -I /usr/lmx-sdk-4.6.1/include/

MSVC:

cl.exe /I “C:\Program Files\X-Formation\LM-X SDK v4.6.1 win64_x64\include\”

Commonly used functions

In the following examples we will present five commonly used LM-X API functions.

LMX_Init

The LMX_Init function initializes the protection system. This function creates a handle needed to use other LM- X API functions. It returns LMX_STATUS variable that indicates initialization status.

LMX_HANDLE LmxHandle;

if (LMX_Init(&LmxHandle) != LMX_SUCCESS)
{
  printf("Unable to initialize!\n");
  return 1;
}

LMX_SetOption

The LMX_SetOption function sets up flags that change licensing behavior prior to license checkout. This function returns LMX_STATUS variable that indicates the status of initialization.

In the following example LMX_SetOption is used to set the license path to the current path.

LMX_SetOption(LmxHandle, LMX_OPT_LICENSE_PATH, ".");

LMX_Checkout

The LMX_Checkout function is one of the most important LMX API functions, because it checks out one or more licenses for a specific feature. This function requires that the feature name, version and the count of the features be defined as shown below.

if (LMX_Checkout(LmxHandle, "feature", 1, 0, 1) != LMX_SUCCESS)
{
  printf("Unable to checkout\n");
  LMX_Free(LmxHandle);
  return 1;
}

LMX_Checkin

The LMX_Checkin function returns the licenses for a single checked out feature or all checked out features.

LMX_Checkin(LmxHandle, "feature", LMX_ALL_LICENSES);

LMX_Free

The LMX_Free function, which has an inverse effect to LMX_Init, frees any allocated memory used by the licensing system and closes any open connection to a license server.

LMX_Free(LmxHandle);

The following example illustrates a basic example of an LM-X licensed application.

#include <stdio.h>
 
#include "lmx.h"
 
int main()
{
  LMX_HANDLE LmxHandle;
 
  if (LMX_Init(&LmxHandle) != LMX_SUCCESS)
  {
    printf("Unable to initialize!\n");
    return 1;
  }
 
  // Look for licenses in current directory.
  LMX_SetOption(LmxHandle, LMX_OPT_LICENSE_PATH, ".");
  if (LMX_Checkout(LmxHandle, "feature", 1, 0, 1) != LMX_SUCCESS)
  {
    printf("Unable to checkout!\n");
    LMX_Free(LmxHandle);
    return 1;
  }
  // Here you are safe to run your licensed features
  "printf("Here you can run your features\n");
 
  LMX_Checkin(LmxHandle, "feature", LMX_ALL_LICENSES);
  LMX_Free(LmxHandle);
  return 0;
}

If you decide to copy and paste the above code block, save it as an example.c.

Compilation

Let's assume you saved your program source code as an example.c and installed your LM-X SDK in the default directory.

To compile your first program run the following: