After linking and enabling the shader program, use the following code to display the list of active attributes:

1. Start by querying for the number of active attributes:

GLint numAttribs; 
glGetProgramInterfaceiv(programHandle, GL_PROGRAM_INPUT,
        GL_ACTIVE_RESOURCES, &numAttribs);

2. Loop through each attribute, query for the length of the name, the type, and the attribute location, and print the results to standard out:

GLenum properties[] = {GL_NAME_LENGTH, GL_TYPE, GL_LOCATION};
 
std::cout << "Active attributes" << std::endl; 
for( int i = 0; i < numAttribs; ++i ) { 
  GLint results[3]; 
  glGetProgramResourceiv(programHhandle, GL_PROGRAM_INPUT,
        i, 3, properties, 3, NULL, results); 
 
  GLint nameBufSize = results[0] + 1; 
  char * name = new char[nameBufSize]; 
  glGetProgramResourceName(programHandle, 
       GL_PROGRAM_INPUT, i, nameBufSize, NULL, name);  
  printf("%-5d %s (%s)n", results[2], name, 
  getTypeString(results[1])); 
  delete [] name; 
}