Description

The purpose of this challenge is to use exception handling constructs.

Requirements

1. Write an exception class that inherits from C++ exception class

   class ConfigFileError : public exception
   {
     public:
       const char * what() const throw()
       {
         return "Configuration file is badly formed";
       }
   };
   

2. Write a class ConfigFileMissingKey, that inherits from ConfigFileError. This class will have a what() function that returns “Missing key”
3. Write a class ConfigFileBadKey, that inherits from ConfigFileError. This class will have a what() function that returns “Bad key specification”
4. Write a class ConfigFileMissingSeparator, that inherits from ConfigFileError. This class will have a what() function that returns “Missing separator”
5. Write a class ConfigFile. This class does not inherit from any  other class.In this class,
   1. create a private function bool contains_separator(string line, char sep = ‘=’). This function will examine line for the presence of sep. Note that, by default, sep contains an equal sign. Do not have the code specifically check for an equal sign. This function returns true if line contains sep, and false otherwise.
   2. create a private function bool is_name_valid(string name). This function returns true if name is a valid name that follows C++ basic variable naming requirements (starts with a letter or underscore) and false otherwise.
   3. create a private function bool is_comment(string line). This function returns true if the first character of line is a semi-colon, and false otherwise.
   4. create a private function bool is_missing_key(string line). This function will return true if line begins with an equal sign, and false otherwise.
   5. create a public function bool load(string filename). This function will read all lines out of filename. The lines of the configuration file passed in filename will be evaluated. Each entry in the file will be checked for correctness and the function will throw exceptions for each failed validation.

      bool load(string filename)
      {
         string line;     // stores a line of text from the file
         // code to read lines of text from a file
      
         // one exception check
         if (!is_name_valid(line))
           throw ConfigFileBadKey();
         // throw the other exceptions calling the exceptions defined earlier
      
         return true;
      }
      

Sample main()

int main()
{
  ConfigFile config;

  try
  {
    if (config.load("config.ini"))
      cout << "Config file verified" << endl;
  }
  catch (ConfigFileMissingKey & ex)
  {
    cerr << ex.what() << endl;
  }
  // add more exception handlers for all exceptions 
  // also add a catch-all handler

  return 0;
}