VILLASnode/common/lib/terminal.cpp

/* Terminal handling.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#include <unistd.h>

#include <villas/exceptions.hpp>
#include <villas/log.hpp>
#include <villas/terminal.hpp>

using namespace villas;

class Terminal *Terminal::current = nullptr;

Terminal::Terminal() {
  int ret;

  window.ws_row = 0;
  window.ws_col = 0;

  isTty = isatty(STDERR_FILENO);

  Logger logger = Log::get("terminal");

  if (isTty) {
    struct sigaction sa_resize;
    sa_resize.sa_flags = SA_SIGINFO;
    sa_resize.sa_sigaction = resize;

    sigemptyset(&sa_resize.sa_mask);

    ret = sigaction(SIGWINCH, &sa_resize, nullptr);
    if (ret)
      throw SystemError("Failed to register signal handler");

    // Try to get initial terminal dimensions
    ret = ioctl(STDERR_FILENO, TIOCGWINSZ, &window);
    if (ret)
      logger->warn("Failed to get terminal dimensions");
  } else {
    logger->info("stderr is not associated with a terminal! Using fallback "
                 "values for window size...");
  }

  // Fallback if for some reason we can not determine a prober window size
  if (window.ws_col == 0)
    window.ws_col = 150;

  if (window.ws_row == 0)
    window.ws_row = 50;
}

void Terminal::resize(int, siginfo_t *, void *) {
  if (!current)
    current = new Terminal();

  Logger logger = Log::get("terminal");

  int ret;

  ret = ioctl(STDERR_FILENO, TIOCGWINSZ, &current->window);
  if (ret)
    throw SystemError("Failed to get terminal dimensions");

  logger->debug("New terminal size: {}x{}", current->window.ws_row,
                current->window.ws_col);
};