public void WriteLine(string format, params object[] args)
{
using (var fd = new PosixFileDescriptor(TtyDeviceName, OpenFlags.O_RDWR))
{
if (fd.IsInvalid)
{
Trace.WriteLine("Not a TTY, abandoning write line.");
return;
}
fd.Write(string.Format(format, args));
fd.Write("\n");
}
}
private string Prompt(string prompt, bool echo)
{
using (var fd = new PosixFileDescriptor(TtyDeviceName, OpenFlags.O_RDWR))
{
if (fd.IsInvalid)
{
Trace.WriteLine("Not a TTY, abandoning prompt.");
return(null);
}
fd.Write($"{prompt}: ");
var sb = new StringBuilder();
using (CreateTtyContext(fd, echo))
{
var readBuf = new byte[1];
bool eol = false;
while (!eol)
{
int nr;
// Read one byte at a time
if ((nr = fd.Read(readBuf, 1)) != 1)
{
// Either we reached end of file or an error occured.
// We don't care which so let's just trace and terminate further reading.
Trace.WriteLine($"Exiting POSIX terminal prompt read-loop unexpectedly (nr={nr})");
eol = true;
break;
}
int c = readBuf[0];
switch (c)
{
case 3: // CTRL + C
// Since `read` is a blocking call we must manually raise the SIGINT signal
// when the user types CTRL+C into the terminal window.
int pid = Unistd.getpid();
Trace.WriteLine($"Intercepted SIGINT during terminal prompt read-loop - sending SIGINT to self (pid={pid})");
Signal.kill(pid, Signal.SIGINT);
break;
case '\n':
eol = true;
// Only need to echo the newline to move the terminal cursor down when
// echo is disabled. When echo is enabled the newline is written for us.
if (!echo)
{
fd.Write("\n");
}
break;
case '\b':
case DeleteChar:
if (sb.Length > 0)
{
sb.Remove(sb.Length - 1, 1);
fd.Write("\b \b");
}
break;
default:
sb.Append((char)c);
break;
}
}
return(sb.ToString());
}
}
}