livetrax/libs/pbd/epa.cc

/*
    Copyright (C) 2010 Paul Davis 

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <cstdlib>
#include <iostream>

#include "pbd/epa.h"

extern char** environ;

using namespace PBD;
using namespace std;

EnvironmentalProtectionAgency* EnvironmentalProtectionAgency::_global_epa = 0;

EnvironmentalProtectionAgency::EnvironmentalProtectionAgency (bool arm)
        : _armed (arm)
{
        if (_armed) {
                save ();
        }
}

EnvironmentalProtectionAgency::~EnvironmentalProtectionAgency()
{
        if (_armed) {
                restore ();
        }
}

void
EnvironmentalProtectionAgency::arm ()
{
        _armed = true;
}

void
EnvironmentalProtectionAgency::save ()
{
        e.clear ();

        for (size_t i = 0; environ[i]; ++i) {

                string estring = environ[i];
                string::size_type equal = estring.find_first_of ('=');

                if (equal == string::npos) {
                        /* say what? an environ value without = ? */
                        continue;
                }

                string before = estring.substr (0, equal);
                string after = estring.substr (equal+1);

                cerr << "Save [" << before << "] = " << after << endl;

                e.insert (pair<string,string>(before,after));
        }
}                         
void
EnvironmentalProtectionAgency::restore () const
{
        for (map<string,string>::const_iterator i = e.begin(); i != e.end(); ++i) {
                cerr << "Restore [" << i->first << "] = " << i->second << endl;
                setenv (i->first.c_str(), i->second.c_str(), 1);
        }
}