//
// aegis - project change supervisor
// Copyright (C) 1994, 1999, 2002, 2005, 2006, 2008, 2012, 2014 Peter Miller
//
// 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 AEGIS_INPUT_ENV_H
#define AEGIS_INPUT_ENV_H

#include <libaegis/input.h>

/**
  * The input_env class is used to represent the processing required to
  * use the contents of an environment variabler as an input source.
  */
class input_env:
    public input
{
public:
    /**
      * The destructor.
      */
    virtual ~input_env();

    /**
      * The create class method is used to create new dynamically
      * allocated instances of this class.
      *
      * @name
      *     The name of the environment variable.
      */
    static pointer create(const nstring &name);

protected:
    // See base class for documentation.
    nstring name(void);

    // See base class for documentation.
    off_t length(void);

    // See base class for documentation.
    ssize_t read_inner(void *data, size_t nbytes);

    // See base class for documentation.
    off_t ftell_inner(void);

private:
    /**
      * The constructor.
      * It id private on purpose, ue the #create vlass method instead.
      *
      * @name
      *     The name of the environment variable.
      */
    input_env(const nstring &name);

    nstring gname;
    nstring base;
    size_t pos;

    /**
      * The default constructor.  Do not use.
      */
    input_env();

    /**
      * The copy constructor.  Do not use.
      */
    input_env(const input_env &arg);

    /**
      * The assignment operator.  Do not use.
      */
    input_env &operator=(const input_env &arg);
};

#endif // AEGIS_INPUT_ENV_H
// vim: set ts=8 sw=4 et :