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//===-- TTYState.cpp --------------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Core/TTYState.h"
#include <fcntl.h>
#include <unistd.h>
#include <sys/signal.h>
using namespace lldb_private;
//----------------------------------------------------------------------
// Default constructor
//----------------------------------------------------------------------
TTYState::TTYState() :
m_fd(-1),
m_tflags(-1),
m_ttystate_err(-1),
m_ttystate(),
m_process_group(-1)
{
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
TTYState::~TTYState()
{
}
//----------------------------------------------------------------------
// Save the current state of the TTY for the file descriptor "fd"
// and if "save_process_group" is true, attempt to save the process
// group info for the TTY.
//----------------------------------------------------------------------
bool
TTYState::Save (int fd, bool save_process_group)
{
if (fd >= 0 && ::isatty (fd))
{
m_fd = fd;
m_tflags = ::fcntl (fd, F_GETFL, 0);
m_ttystate_err = ::tcgetattr (fd, &m_ttystate);
if (save_process_group)
m_process_group = ::tcgetpgrp (0);
else
m_process_group = -1;
}
else
{
m_fd = -1;
m_tflags = -1;
m_ttystate_err = -1;
m_process_group = -1;
}
return m_ttystate_err == 0;
}
//----------------------------------------------------------------------
// Restore the state of the TTY using the cached values from a
// previous call to Save().
//----------------------------------------------------------------------
bool
TTYState::Restore () const
{
int result = 0;
if (IsValid())
{
if (TFlagsIsValid())
result = fcntl (m_fd, F_SETFL, m_tflags);
if (TTYStateIsValid())
result = tcsetattr (m_fd, TCSANOW, &m_ttystate);
if (ProcessGroupIsValid())
{
// Save the original signal handler.
void (*saved_sigttou_callback) (int) = NULL;
saved_sigttou_callback = (void (*)(int)) signal (SIGTTOU, SIG_IGN);
// Set the process group
result = tcsetpgrp (m_fd, m_process_group);
// Restore the original signal handler.
signal (SIGTTOU, saved_sigttou_callback);
}
return true;
}
return false;
}
//----------------------------------------------------------------------
// Returns true if this object has valid saved TTY state settings
// that can be used to restore a previous state.
//----------------------------------------------------------------------
bool
TTYState::IsValid() const
{
return (m_fd >= 0) && (TFlagsIsValid() || TTYStateIsValid());
}
//----------------------------------------------------------------------
// Returns true if m_tflags is valid
//----------------------------------------------------------------------
bool
TTYState::TFlagsIsValid() const
{
return m_tflags != -1;
}
//----------------------------------------------------------------------
// Returns true if m_ttystate is valid
//----------------------------------------------------------------------
bool
TTYState::TTYStateIsValid() const
{
return m_ttystate_err == 0;
}
//----------------------------------------------------------------------
// Returns true if m_process_group is valid
//----------------------------------------------------------------------
bool
TTYState::ProcessGroupIsValid() const
{
return m_process_group != -1;
}
//------------------------------------------------------------------
// Constructor
//------------------------------------------------------------------
TTYStateSwitcher::TTYStateSwitcher () :
m_currentState(UINT32_MAX)
{
}
//------------------------------------------------------------------
// Destructor
//------------------------------------------------------------------
TTYStateSwitcher::~TTYStateSwitcher ()
{
}
//------------------------------------------------------------------
// Returns the number of states that this switcher contains
//------------------------------------------------------------------
uint32_t
TTYStateSwitcher::GetNumberOfStates() const
{
return sizeof(m_ttystates)/sizeof(TTYState);
}
//------------------------------------------------------------------
// Restore the state at index "idx".
//
// Returns true if the restore was successful, false otherwise.
//------------------------------------------------------------------
bool
TTYStateSwitcher::Restore (uint32_t idx) const
{
const uint32_t num_states = GetNumberOfStates();
if (idx >= num_states)
return false;
// See if we already are in this state?
if (m_currentState < num_states && (idx == m_currentState) && m_ttystates[idx].IsValid())
return true;
// Set the state to match the index passed in and only update the
// current state if there are no errors.
if (m_ttystates[idx].Restore())
{
m_currentState = idx;
return true;
}
// We failed to set the state. The tty state was invalid or not
// initialized.
return false;
}
//------------------------------------------------------------------
// Save the state at index "idx" for file descriptor "fd" and
// save the process group if requested.
//
// Returns true if the restore was successful, false otherwise.
//------------------------------------------------------------------
bool
TTYStateSwitcher::Save (uint32_t idx, int fd, bool save_process_group)
{
const uint32_t num_states = GetNumberOfStates();
if (idx < num_states)
return m_ttystates[idx].Save(fd, save_process_group);
return false;
}
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