This code works to find starting and ending pointer to highlight matched license text as scanned by scancode.

text_highlighting.cpp

unsigned long getFilePointer(const string& filename,
  size_t start_line, 
  const string& match_text){
  ifstream checkfile(filename);
  string str;
  if(checkfile.is_open()){
    for (size_t i = 0; i <start_line-1; i++)
    {
      getline(checkfile, str);
    }
    int file_p = checkfile.tellg();
    getline(checkfile, str);
    cout<< "Checkline="<<str<<"\n";
    unsigned int pos= str.find(match_text);
    if(pos!=string::npos){

      return file_p+pos;
    }
  }
  return -1;
}