watch: Use alternate buffer to display output

This commit is contained in:
Tim Ledbetter 2023-07-13 17:06:08 +01:00 committed by Andreas Kling
parent ba1c4bc1d1
commit d0fd925126

View file

@ -26,6 +26,33 @@ static bool flag_beep_on_fail = false;
static int volatile exit_code = 0;
static volatile pid_t child_pid = -1;
static struct termios g_save;
static ErrorOr<void> setup_tty()
{
// Save previous tty settings.
g_save = TRY(Core::System::tcgetattr(STDOUT_FILENO));
struct termios raw = g_save;
raw.c_lflag &= ~(ECHO | ICANON);
// Disable echo and line buffering
TRY(Core::System::tcsetattr(STDOUT_FILENO, TCSAFLUSH, raw));
// Save cursor and switch to alternate buffer.
out("\e[s\e[?1047h");
return {};
}
static void teardown_tty()
{
auto maybe_error = Core::System::tcsetattr(STDOUT_FILENO, TCSAFLUSH, g_save);
if (maybe_error.is_error())
warnln("Failed to reset original terminal state: {}", strerror(maybe_error.error().code()));
out("\e[?1047l\e[u");
}
static DeprecatedString build_header_string(Vector<DeprecatedString> const& command, Duration const& interval)
{
StringBuilder builder;
@ -59,6 +86,10 @@ static void handle_signal(int signal)
exit_code = 1;
}
}
auto is_a_tty_or_error = Core::System::isatty(STDOUT_FILENO);
if (!is_a_tty_or_error.is_error() && is_a_tty_or_error.value())
teardown_tty();
exit(exit_code);
}
@ -102,8 +133,7 @@ static int run_command(Vector<DeprecatedString> const& command)
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
TRY(Core::System::signal(SIGINT, handle_signal));
TRY(Core::System::pledge("stdio proc exec rpath"));
TRY(Core::System::pledge("stdio proc exec rpath tty sigaction"));
Vector<DeprecatedString> files_to_watch;
Vector<DeprecatedString> command;
@ -128,6 +158,14 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
args_parser.add_positional_argument(command, "Command to run", "command");
args_parser.parse(arguments);
if (TRY(Core::System::isatty(STDOUT_FILENO)))
TRY(setup_tty());
struct sigaction quit_action;
quit_action.sa_handler = handle_signal;
TRY(Core::System::sigaction(SIGTERM, &quit_action, nullptr));
TRY(Core::System::sigaction(SIGINT, &quit_action, nullptr));
DeprecatedString header;
auto watch_callback = [&] {
@ -175,7 +213,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
}
}
} else {
TRY(Core::System::pledge("stdio proc exec"));
TRY(Core::System::pledge("stdio proc exec tty"));
Duration interval;
if (opt_interval <= 0) {