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//===-- TTYState.cpp --------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Created by Greg Clayton on 3/26/07.
//
//===----------------------------------------------------------------------===//
#include "TTYState.h"
#include <fcntl.h>
#include <sys/signal.h>
#include <unistd.h>
TTYState::TTYState()
: m_fd(-1), m_tflags(-1), m_ttystateErr(-1), m_processGroup(-1) {}
TTYState::~TTYState() {}
bool TTYState::GetTTYState(int fd, bool saveProcessGroup) {
if (fd >= 0 && ::isatty(fd)) {
m_fd = fd;
m_tflags = fcntl(fd, F_GETFL, 0);
m_ttystateErr = tcgetattr(fd, &m_ttystate);
if (saveProcessGroup)
m_processGroup = tcgetpgrp(0);
else
m_processGroup = -1;
} else {
m_fd = -1;
m_tflags = -1;
m_ttystateErr = -1;
m_processGroup = -1;
}
return m_ttystateErr == 0;
}
bool TTYState::SetTTYState() const {
int result = 0;
if (IsValid()) {
if (TFlagsValid())
result = fcntl(m_fd, F_SETFL, m_tflags);
if (TTYStateValid())
result = tcsetattr(m_fd, TCSANOW, &m_ttystate);
if (ProcessGroupValid()) {
// 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_processGroup);
// Restore the original signal handler.
signal(SIGTTOU, saved_sigttou_callback);
}
return true;
}
return false;
}
TTYStateSwitcher::TTYStateSwitcher() : m_currentState(~0) {}
TTYStateSwitcher::~TTYStateSwitcher() {}
bool TTYStateSwitcher::GetState(uint32_t idx, int fd, bool saveProcessGroup) {
if (ValidStateIndex(idx))
return m_ttystates[idx].GetTTYState(fd, saveProcessGroup);
return false;
}
bool TTYStateSwitcher::SetState(uint32_t idx) const {
if (!ValidStateIndex(idx))
return false;
// See if we already are in this state?
if (ValidStateIndex(m_currentState) && (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].SetTTYState()) {
m_currentState = idx;
return true;
}
// We failed to set the state. The tty state was invalid or not
// initialized.
return false;
}
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