cpp-syslog.h

/*************************************************************************
 ** Copyright (C) 2014 Jan Pedersen <jp@jp-embedded.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 3 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, see <http://www.gnu.org/licenses/>.
 *************************************************************************/

#ifndef __syslog
#define __syslog

#include <iostream>
#include <streambuf>
#include <string>
namespace csyslog {
#include <syslog.h>
}

namespace syslog
{
        struct level {
                enum pri {
                        emerg   = LOG_EMERG,    // A panic condition
                        alert   = LOG_ALERT,    // A condition that should be corrected
                        critical= LOG_CRIT,     // Critical condition, e.g, hard device error
                        error   = LOG_ERR,      // Errors
                        warning = LOG_WARNING,  // Warning messages
                        notice  = LOG_NOTICE,   // Possibly be handled specially
                        info    = LOG_INFO,     // Informational
                        debug   = LOG_DEBUG     // For debugging program
                };
        };

        class streambuf : public std::streambuf
        {
                std::string _buf;
                int _level;

                public:

                streambuf() : _level(level::debug)      { }
                void level(int level)                   { _level = level; }

                protected:

                int sync()
                {
                        if (_buf.size()) {
                                csyslog::syslog(_level, "%s", _buf.c_str());
                                _buf.erase();
                        }       
                        return 0;
                }

                int_type overflow(int_type c)
                {
                        if(c == traits_type::eof()) sync();
                        else _buf += static_cast<char>(c);
                        return c;
                }

        };

        class ostream : public std::ostream
        {
                streambuf _logbuf;
                public:
                ostream() : std::ostream(&_logbuf) {}
                ostream& operator<<(const level::pri lev) { _logbuf.level(lev); return *this; }
        };

        class redirect
        {
                ostream dst;
                std::ostream &src;
                std::streambuf * const sbuf;

                public:
                redirect(std::ostream & src) : src(src), sbuf(src.rdbuf(dst.rdbuf())) { dst << (src == std::cout ? level::info : level::error); }
                ~redirect() { src.rdbuf(sbuf); }
        };
}

#endif