Adding pipe communication with ArGaze main script.

1 files changed, 32 insertions, 1 deletions

diff --git a/src/argaze/__main__.py b/src/argaze/__main__.py
index 96fda23..127baa8 100644
--- a/src/argaze/__main__.py
+++ b/src/argaze/__main__.py
@@ -20,6 +20,7 @@ import argparse
 import logging
 import json
 import contextlib
+import os
 
 from . import load
 from .ArFeatures import ArCamera, ArContext
@@ -30,12 +31,25 @@ import cv2
 parser = argparse.ArgumentParser(description=__doc__.split('-')[0])
 parser.add_argument('context_file', metavar='CONTEXT_FILE', type=str, help='JSON context filepath')
 parser.add_argument('-v', '--verbose', action='store_true', default=False, help='enable verbose mode to print information in console')
+parser.add_argument('-p', '--pipe_path', metavar='PIPE_PATH', type=str, default=None, help='enable pipe communication at given path to execute external commands')
 
 args = parser.parse_args()
 
 # Manage logging
 logging.basicConfig(format='%(levelname)s: %(message)s', level=logging.DEBUG if args.verbose else logging.INFO)
 
+# Manage pipe communication
+if args.pipe_path is not None:
+
+	if not os.path.exists(args.pipe_path):
+
+	    os.mkfifo(args.pipe_path)
+
+	# Open the fifo in non-blocking mode or it will stalls until someone opens it for writting
+	pipe_file = os.open(args.pipe_path, os.O_RDONLY | os.O_NONBLOCK)
+
+	logging.info('%s pipe opened', args.pipe_path)
+
 # Load context from JSON file
 with load(args.context_file) as context:
 
@@ -52,11 +66,28 @@ with load(args.context_file) as context:
 	cv2.namedWindow(context.name, cv2.WINDOW_AUTOSIZE)
 
 	# Waiting for 'ctrl+C' interruption
-	with contextlib.suppress(KeyboardInterrupt):
+	with contextlib.suppress(KeyboardInterrupt), os.fdopen(pipe_file) as pipe:
 
 		# Visualization loop
 		while True:
 
+			# Read message from pipe if required
+			if args.pipe_path is not None:
+
+				message = pipe.read().rstrip('\n')
+
+				if message:
+
+					logging.info('%s: %s', args.pipe_path, message)
+
+					try:
+
+						exec(message)
+
+					except Exception as e:
+
+						logging.error('%s', e)
+
 			# Display context
 			cv2.imshow(context.name, context.image())