config.cpp

// Config.cpp

#include "config.h"

using namespace std;


Config::Config( string filename, string delimiter,
			   string comment )
			   : m_Delimiter(delimiter), m_Comment(comment)
{
	// Construct a Config, getting keys and values from given file

	std::ifstream in( filename.c_str() );

	if( !in ) throw File_not_found( filename ); 

	in >> (*this);
}


Config::Config()
: m_Delimiter( string(1,'=') ), m_Comment( string(1,'#') )
{
	// Construct a Config without a file; empty
}



bool Config::KeyExists( const string& key ) const
{
	// Indicate whether key is found
	mapci p = m_Contents.find( key );
	return ( p != m_Contents.end() );
}


/* static */
void Config::Trim( string& inout_s )
{
	// Remove leading and trailing whitespace
	static const char whitespace[] = " \n\t\v\r\f";
	inout_s.erase( 0, inout_s.find_first_not_of(whitespace) );
	inout_s.erase( inout_s.find_last_not_of(whitespace) + 1U );
}


std::ostream& operator<<( std::ostream& os, const Config& cf )
{
	// Save a Config to os
	for( Config::mapci p = cf.m_Contents.begin();
		p != cf.m_Contents.end();
		++p )
	{
		os << p->first << " " << cf.m_Delimiter << " ";
		os << p->second << std::endl;
	}
	return os;
}

void Config::Remove( const string& key )
{
	// Remove key and its value
	m_Contents.erase( m_Contents.find( key ) );
	return;
}

std::istream& operator>>( std::istream& is, Config& cf )
{
	// Load a Config from is
	// Read in keys and values, keeping internal whitespace
	typedef string::size_type pos;
	const string& delim  = cf.m_Delimiter;  // separator
	const string& comm   = cf.m_Comment;    // comment
	const pos skip = delim.length();        // length of separator

	string nextline = "";  // might need to read ahead to see where value ends

	while( is || nextline.length() > 0 )
	{
		// Read an entire line at a time
		string line;
		if( nextline.length() > 0 )
		{
			line = nextline;  // we read ahead; use it now
			nextline = "";
		}
		else
		{
			std::getline( is, line );
		}

		// Ignore comments
		line = line.substr( 0, line.find(comm) );

		// Parse the line if it contains a delimiter
		pos delimPos = line.find( delim );
		if( delimPos < string::npos )
		{
			// Extract the key
			string key = line.substr( 0, delimPos );
			line.replace( 0, delimPos+skip, "" );

			// See if value continues on the next line
			// Stop at blank line, next line with a key, end of stream,
			// or end of file sentry
			bool terminate = false;
			while( !terminate && is )
			{
				std::getline( is, nextline );
				terminate = true;

				string nlcopy = nextline;
				Config::Trim(nlcopy);
				if( nlcopy == "" ) continue;

				nextline = nextline.substr( 0, nextline.find(comm) );
				if( nextline.find(delim) != string::npos )
					continue;

				nlcopy = nextline;
				Config::Trim(nlcopy);
				if( nlcopy != "" ) line += "\n";
				line += nextline;
				terminate = false;
			}

			// Store key and value
			Config::Trim(key);
			Config::Trim(line);
			cf.m_Contents[key] = line;  // overwrites if key is repeated
		}
	}

	return is;
}
bool Config::FileExist(std::string filename)
{
	bool exist= false;
	std::ifstream in( filename.c_str() );
	if( in ) 
		exist = true;
	return exist;
}

void Config::ReadFile( string filename, string delimiter,
					  string comment )
{
	m_Delimiter = delimiter;
	m_Comment = comment;
	std::ifstream in( filename.c_str() );

	if( !in ) throw File_not_found( filename ); 

	in >> (*this);
}