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from __future__ import annotations
import argparse
import os
import signal
import sys
import threading
try:
import readline # noqa: F401
except ImportError: # Windows has no `readline` normally
pass
from .sync.client import ClientConnection, connect
from .version import version as websockets_version
if sys.platform == "win32":
def win_enable_vt100() -> None:
"""
Enable VT-100 for console output on Windows.
See also https://bugs.python.org/issue29059.
"""
import ctypes
STD_OUTPUT_HANDLE = ctypes.c_uint(-11)
INVALID_HANDLE_VALUE = ctypes.c_uint(-1)
ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x004
handle = ctypes.windll.kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
if handle == INVALID_HANDLE_VALUE:
raise RuntimeError("unable to obtain stdout handle")
cur_mode = ctypes.c_uint()
if ctypes.windll.kernel32.GetConsoleMode(handle, ctypes.byref(cur_mode)) == 0:
raise RuntimeError("unable to query current console mode")
# ctypes ints lack support for the required bit-OR operation.
# Temporarily convert to Py int, do the OR and convert back.
py_int_mode = int.from_bytes(cur_mode, sys.byteorder)
new_mode = ctypes.c_uint(py_int_mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING)
if ctypes.windll.kernel32.SetConsoleMode(handle, new_mode) == 0:
raise RuntimeError("unable to set console mode")
def print_during_input(string: str) -> None:
sys.stdout.write(
# Save cursor position
"\N{ESC}7"
# Add a new line
"\N{LINE FEED}"
# Move cursor up
"\N{ESC}[A"
# Insert blank line, scroll last line down
"\N{ESC}[L"
# Print string in the inserted blank line
f"{string}\N{LINE FEED}"
# Restore cursor position
"\N{ESC}8"
# Move cursor down
"\N{ESC}[B"
)
sys.stdout.flush()
def print_over_input(string: str) -> None:
sys.stdout.write(
# Move cursor to beginning of line
"\N{CARRIAGE RETURN}"
# Delete current line
"\N{ESC}[K"
# Print string
f"{string}\N{LINE FEED}"
)
sys.stdout.flush()
def print_incoming_messages(websocket: ClientConnection, stop: threading.Event) -> None:
for message in websocket:
if isinstance(message, str):
print_during_input("< " + message)
else:
print_during_input("< (binary) " + message.hex())
if not stop.is_set():
# When the server closes the connection, raise KeyboardInterrupt
# in the main thread to exit the program.
if sys.platform == "win32":
ctrl_c = signal.CTRL_C_EVENT
else:
ctrl_c = signal.SIGINT
os.kill(os.getpid(), ctrl_c)
def main() -> None:
# Parse command line arguments.
parser = argparse.ArgumentParser(
prog="python -m websockets",
description="Interactive WebSocket client.",
add_help=False,
)
group = parser.add_mutually_exclusive_group()
group.add_argument("--version", action="store_true")
group.add_argument("uri", metavar="<uri>", nargs="?")
args = parser.parse_args()
if args.version:
print(f"websockets {websockets_version}")
return
if args.uri is None:
parser.error("the following arguments are required: <uri>")
# If we're on Windows, enable VT100 terminal support.
if sys.platform == "win32":
try:
win_enable_vt100()
except RuntimeError as exc:
sys.stderr.write(
f"Unable to set terminal to VT100 mode. This is only "
f"supported since Win10 anniversary update. Expect "
f"weird symbols on the terminal.\nError: {exc}\n"
)
sys.stderr.flush()
try:
websocket = connect(args.uri)
except Exception as exc:
print(f"Failed to connect to {args.uri}: {exc}.")
sys.exit(1)
else:
print(f"Connected to {args.uri}.")
stop = threading.Event()
# Start the thread that reads messages from the connection.
thread = threading.Thread(target=print_incoming_messages, args=(websocket, stop))
thread.start()
# Read from stdin in the main thread in order to receive signals.
try:
while True:
# Since there's no size limit, put_nowait is identical to put.
message = input("> ")
websocket.send(message)
except (KeyboardInterrupt, EOFError): # ^C, ^D
stop.set()
websocket.close()
print_over_input("Connection closed.")
thread.join()
if __name__ == "__main__":
main()
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