//===-- PseudoTerminal.h ----------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  Created by Greg Clayton on 1/8/08.
//
//===----------------------------------------------------------------------===//

#ifndef __PseudoTerminal_h__
#define __PseudoTerminal_h__

#include <fcntl.h>
#include <termios.h>
#include <string>

class PseudoTerminal
{
public:
    enum {
        invalid_fd = -1,
        invalid_pid = -1
    };

    enum Error
    {
        success                                     = 0,
        err_posix_openpt_failed                     = -2,
        err_grantpt_failed                          = -3,
        err_unlockpt_failed                         = -4,
        err_ptsname_failed                          = -5,
        err_open_slave_failed                       = -6,
        err_fork_failed                             = -7,
        err_setsid_failed                           = -8,
        err_failed_to_acquire_controlling_terminal  = -9,
        err_dup2_failed_on_stdin                    = -10,
        err_dup2_failed_on_stdout                   = -11,
        err_dup2_failed_on_stderr                   = -12
    };
    //------------------------------------------------------------------
    // Constructors and Destructors
    //------------------------------------------------------------------
                PseudoTerminal ();
                ~PseudoTerminal ();

    void        CloseMaster ();
    void        CloseSlave ();
    Error       OpenFirstAvailableMaster (int oflag);
    Error       OpenSlave (int oflag);
    int         MasterFD () const { return m_master_fd; }
    int         SlaveFD () const { return m_slave_fd; }
    int         ReleaseMasterFD ()
                {
                    // Release ownership of the master pseudo terminal file
                    // descriptor without closing it. (the destructor for this
                    // class will close it otherwise!)
                    int fd = m_master_fd;
                    m_master_fd = invalid_fd;
                    return fd;
                }
    int         ReleaseSlaveFD ()
                {
                    // Release ownership of the slave pseudo terminal file
                    // descriptor without closing it (the destructor for this
                    // class will close it otherwise!)
                    int fd = m_slave_fd;
                    m_slave_fd = invalid_fd;
                    return fd;
                }

    const char* SlaveName () const;

    pid_t       Fork(Error& error);
protected:
    //------------------------------------------------------------------
    // Classes that inherit from PseudoTerminal can see and modify these
    //------------------------------------------------------------------
    int m_master_fd;
    int m_slave_fd;

private:
    //------------------------------------------------------------------
    // Outlaw copy and assignment constructors
    //------------------------------------------------------------------
    PseudoTerminal(const PseudoTerminal& rhs);
    PseudoTerminal& operator=(const PseudoTerminal& rhs);

};

#endif // #ifndef __PseudoTerminal_h__