/* This file is part of the KDE libraries

    Copyright (C) 2003,2007 Oswald Buddenhagen <ossi@kde.org>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#ifndef kpty_h
#define kpty_h

#include "kpty_export.h"

struct KPtyPrivate;
struct termios;

/**
 * Provides primitives for opening & closing a pseudo TTY pair, assigning the
 * controlling TTY, utmp registration and setting various terminal attributes.
 */
class KPTY_EXPORT KPty {
    Q_DECLARE_PRIVATE(KPty)

public:

  /**
   * Constructor
   */
  KPty();

  /**
   * Destructor:
   *
   *  If the pty is still open, it will be closed. Note, however, that
   *  an utmp registration is @em not undone.
  */
  ~KPty();

  /**
   * Create a pty master/slave pair.
   *
   * @return true if a pty pair was successfully opened
   */
  bool open();

  /**
   * Open using an existing pty master.
   *
   * @param fd an open pty master file descriptor.
   *   The ownership of the fd remains with the caller;
   *   it will not be automatically closed at any point.
   * @return true if a pty pair was successfully opened
   */
  bool open(int fd);

  /**
   * Close the pty master/slave pair.
   */
  void close();

  /**
   * Close the pty slave descriptor.
   *
   * When creating the pty, KPty also opens the slave and keeps it open.
   * Consequently the master will never receive an EOF notification.
   * Usually this is the desired behavior, as a closed pty slave can be
   * reopened any time - unlike a pipe or socket. However, in some cases
   * pipe-alike behavior might be desired.
   *
   * After this function was called, slaveFd() and setCTty() cannot be
   * used.
   */
  void closeSlave();

  /**
   * Open the pty slave descriptor.
   *
   * This undoes the effect of closeSlave().
   *
   * @return true if the pty slave was successfully opened
   */
  bool openSlave();

  /**
   * Creates a new session and process group and makes this pty the
   * controlling tty.
   */
  void setCTty();

  /**
   * Creates an utmp entry for the tty.
   * This function must be called after calling setCTty and
   * making this pty the stdin.
   * @param user the user to be logged on
   * @param remotehost the host from which the login is coming. This is
   *  @em not the local host. For remote logins it should be the hostname
   *  of the client. For local logins from inside an X session it should
   *  be the name of the X display. Otherwise it should be empty.
   */
  void login(const char *user = 0, const char *remotehost = 0);

  /**
   * Removes the utmp entry for this tty.
   */
  void logout();

  /**
   * Wrapper around tcgetattr(3).
   *
   * This function can be used only while the PTY is open.
   * You will need an #include &lt;termios.h&gt; to do anything useful
   * with it.
   *
   * @param ttmode a pointer to a termios structure.
   *  Note: when declaring ttmode, @c struct @c ::termios must be used -
   *  without the '::' some version of HP-UX thinks, this declares
   *  the struct in your class, in your method.
   * @return @c true on success, false otherwise
   */
  bool tcGetAttr(struct ::termios *ttmode) const;

  /**
   * Wrapper around tcsetattr(3) with mode TCSANOW.
   *
   * This function can be used only while the PTY is open.
   *
   * @param ttmode a pointer to a termios structure.
   * @return @c true on success, false otherwise. Note that success means
   *  that @em at @em least @em one attribute could be set.
   */
  bool tcSetAttr(struct ::termios *ttmode);

  /**
   * Change the logical (screen) size of the pty.
   * The default is 24 lines by 80 columns.
   *
   * This function can be used only while the PTY is open.
   *
   * @param lines the number of rows
   * @param columns the number of columns
   * @return @c true on success, false otherwise
   */
  bool setWinSize(int lines, int columns);

  /**
   * Set whether the pty should echo input.
   *
   * Echo is on by default.
   * If the output of automatically fed (non-interactive) PTY clients
   * needs to be parsed, disabling echo often makes it much simpler.
   *
   * This function can be used only while the PTY is open.
   *
   * @param echo true if input should be echoed.
   * @return @c true on success, false otherwise
   */
  bool setEcho(bool echo);

  /**
   * @return the name of the slave pty device.
   *
   * This function should be called only while the pty is open.
   */
  const char *ttyName() const;

  /**
   * @return the file descriptor of the master pty
   *
   * This function should be called only while the pty is open.
   */
  int masterFd() const;

  /**
   * @return the file descriptor of the slave pty
   *
   * This function should be called only while the pty slave is open.
   */
  int slaveFd() const;

protected:
  /**
   * @internal
   */
  KPty(KPtyPrivate *d);

  /**
   * @internal
   */
  KPtyPrivate * const d_ptr;
};

#endif

