/**
* ELog.h
* Copyright (C) 2002 Daniel Karrels <dan@karrels.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*
* $Id: ELog.h,v 1.8 2005/02/20 15:49:21 dan_karrels Exp $
*/
#ifndef __ELOG_H
#define __ELOG_H "$Id: ELog.h,v 1.8 2005/02/20 15:49:21 dan_karrels Exp $"
#include <iostream>
#include <fstream>
#include <string>
namespace gnuworld
{
/**
* This class handles logging for GNUWorld. It maintains a pointer
* to a C++ output stream. If this pointer is non-NULL, all messages
* are logged to this stream. All messages are also logged to the
* file whose name is specified in the constructor.
*/
class ELog
{
protected:
typedef std::ostream& (*__E_omanip)( std::ostream& ) ;
typedef std::ostream& (*__E_manip)( std::ios& ) ;
/**
* A pointer to a C++ output stream for logging. If this
* stream is non-NULL, then all messages will be logged
* to this stream.
*/
std::ostream *outStream ;
/**
* The file output stream to which to log all messages.
*/
std::ofstream outFile ;
/**
* True if logging to an output file.
*/
bool logFile ;
public:
/**
* Instantiate an instance of this class. No output file
* is opened, and no output stream is specified for
* logging.
*/
ELog() ;
/**
* Instantiate an instance of this class, specifying the
* name of the file to which to log messages. This log file
* will be created if it does not already exist. If it
* exists, it will be truncated.
*/
ELog( const std::string& ) ;
/**
* Destroy an instance of this class. This method will
* close the output file if it is open.
*/
virtual ~ELog() ;
/**
* Open an output file for logging messages. If an output
* file is currently open, it will be flushed and closed.
* This method will create the file if it does not already
* exist, otherwise the existing file will be truncated.
* This method returns true on success, false otherwise.
* Keep in mind that even if this method return false,
* any existing output file will be closed.
*/
bool openFile( const std::string& fileName ) ;
/**
* Close the output log file, if it is open.
*/
void closeFile() ;
/**
* Return true if an output log file is open, false otherwise.
* For some reason, std::fstream::is_open() is not const.
*/
inline bool isOpen()
{ return (logFile && outFile.is_open()) ; }
/**
* Use this method to specify which stream to which
* to log messages. Specifying NULL will stop all
* output logging to any stream (except for the output file,
* if it exists).
*/
inline void setStream( std::ostream* newStream )
{ outStream = newStream ; }
/**
* Output the endl function.
*/
ELog& operator<<( __E_omanip func ) ;
/**
* Output the endl function.
*/
ELog& operator<<( __E_manip func ) ;
/**
* Output any other type supported by std::ostream.
*/
template< typename T >
ELog& operator<<( const T& var )
{
if( logFile ) outFile << var ;
if( outStream ) *outStream << var ;
return *this ;
}
} ;
/// The global logging instance.
extern ELog elog ;
} // namespace gnuworld
#endif // __ELOG_H