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/*-*-c++-*-
* $Id$
*
* This file is part of plptools.
*
* Copyright (C) 1999 Philip Proudman <philip.proudman@btinternet.com>
* Copyright (C) 1999-2001 Fritz Elfert <felfert@to.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
*
*/
#ifndef _LOG_H_
#define _LOG_H_
#include <cstdio>
#include <iostream>
#include <syslog.h>
/**
* A streambuffer, logging via syslog
*
* logbuf can be used, if you want to use syslog for
* logging but don't want to change all your nice
* C++-style output statements in your code.
*
* Here is an example showing the usage of logbuf:
*
* <PRE>
* openlog("myDaemon", LOG_CONS|LOG_PID, LOG_DAEMON);
* logbuf ebuf(LOG_ERR, 2);
* ostream lerr(&ebuf);
*
* ... some code ...
*
* lerr << "Whoops, got an error" << endl;
* </PRE>
*
* The second optional argument of the constructor can be used
* to switch the output destination between syslog and some
* file. If it is omitted or set to -1, logging can be switched on
* or off. The initial state is on.
*/
class logbuf : public std::streambuf {
public:
/**
* Constructs a new instance.
*
* @param loglevel The log level for this instance.
* see syslog(3) for symbolic names to use.
* @param fd An optional file descriptor to use
* if switched off.
*/
logbuf(int loglevel, int fd = -1);
/**
* Switches loggin on or off.
*
* @param newstate The desired state.
*/
void setOn(bool newstate) { _on = newstate; }
/**
* Modifies the loglevel of this instance.
*
* @param newlevel The new loglevel.
*/
void setLevel(int newlevel) { _level = newlevel; }
/**
* Retrieve the current state.
*
* @returns The current state.
*/
bool on() { return _on; }
/**
* Retrieves the current loglevel.
*
* @returns The current loglevel.
*/
int level() { return _level; }
/**
* Called by the associated
* ostream to write a character.
* Stores the character in a buffer
* and calls syslog(level, buffer)
* whenever a LF is seen.
*/
int overflow(int c = EOF);
private:
/**
* Pointer to next char in buffer.
*/
char *ptr;
/**
* Current length of buffer.
*/
unsigned int len;
/**
* The log level to use with syslog.
*/
int _level;
/**
* File descriptor to use when switched off.
* If this is -1, don't output anything.
*/
int _fd;
/**
* Log flag.
*/
bool _on;
/**
* The internal buffer for holding
* messages.
*/
char buf[1024];
};
#endif
/*
* Local variables:
* c-basic-offset: 4
* End:
*/
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