Fix stdin to use a pty on Unix

This prevents the internal shell from trying to buffer stdin, causing
none of the data piped into it to actually go through until the process
is closed.

The holdover is only required on Unix. Windows doesn't support PTY but
it also doesn't seem to care and never buffers stdin as far as I can see
anyway.

Author: scarletcafe

jishaku/features/shell.py

@@ -84,9 +84,12 @@ def __init__(self, reader: ShellReader, *args: typing.Any, **kwargs: typing.Any)
         async def on_submit(self, interaction: discord.Interaction, /):
             value = self.stdin_content.value or ""
 
-            if self.reader.process.stdin and self.reader.process.stdin.writable():
-                self.reader.process.stdin.write(f"{value}\r".encode('utf-8'))
-                self.reader.process.stdin.flush()
+            if self.reader.stdin and self.reader.stdin.writable():
+                if sys.platform == "win32":
+                    self.reader.stdin.write(f"{value}\r\n".encode('utf-8'))
+                else:
+                    self.reader.stdin.write(f"{value}\r".encode('utf-8'))
+                self.reader.stdin.flush()
 
                 await interaction.response.send_message(
                     content="Sent into stdin",

jishaku/shell.py

@@ -74,19 +74,36 @@ def __init__(
                 self.highlight = "cmd"
             # Windows doesn't use ANSI codes
             self.escape_ansi = True
+
+            self.process = subprocess.Popen(  # pylint: disable=consider-using-with
+                sequence,
+                stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE
+            )
+
+            self.stdin = self.process.stdin
+            self.stdout = self.process.stdout
         else:
+            import pty  # pylint: disable=import-outside-toplevel
+
             sequence = [SHELL, '-c', code]
             self.ps1 = "$"
             self.highlight = "ansi"
             self.escape_ansi = escape_ansi
 
-        self.process = subprocess.Popen(sequence, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)  # pylint: disable=consider-using-with
+            master_in, slave_in = pty.openpty()
+            self.process = subprocess.Popen(  # pylint: disable=consider-using-with
+                sequence,
+                stdin=slave_in, stdout=subprocess.PIPE, stderr=subprocess.PIPE
+            )
+            self.stdin = os.fdopen(master_in, 'wb')
+            self.stdout = self.process.stdout
+
         self.close_code = None
 
         self.loop = loop or asyncio.get_event_loop()
         self.timeout = timeout
 
-        self.stdout_task = self.make_reader_task(self.process.stdout, self.stdout_handler) if self.process.stdout else None
+        self.stdout_task = self.make_reader_task(self.stdout, self.stdout_handler) if self.process.stdout else None
         self.stderr_task = self.make_reader_task(self.process.stderr, self.stderr_handler) if self.process.stderr else None
 
         self.queue: 'asyncio.Queue[str]' = asyncio.Queue(maxsize=250)