class ExportManager {

    public String addVariable(String line) {
        Matcher variableMatcher = exportPattern.matcher(line);
        if (variableMatcher.matches()) {
            String name = variableMatcher.group(2);
            String value = variableMatcher.group(3);
            if (value.contains(String.valueOf(DOLLAR + name))) {
                value = value.replace(String.valueOf(DOLLAR + name), variables.get(name));
            }
            variables.put(name, value);
            if(listener != null)
                listener.exportChange(name, value);
            return null;
        }
        return "export: usage: export [name[=value] ...]";
    }

    public  ExportManager(File exportFile);
    public  ExportManager(File exportFile, ExportChangeListener listener);
    public  ExportManager(File exportFile, boolean exportUsesSystemEnvironment);
    public  ExportManager(File exportFile, boolean exportUsesSystemEnvironment, ExportChangeListener listener);

}