Fix return codes, add version

wireviz_kroki.py

@@ -1,33 +1,48 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
-import sys
+import sys, io
 import argparse
+import traceback
 import wireviz.wireviz as wv
+from wireviz import __version__
 
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description=
 """Wireviz Kroki wrapper.
 Reads YAML data from stdin and writes output to stdout.
 Errors and messages from WireViz are printed to stderr.""")   
-    
+
     output_formats = ["svg", "png", "harness"]
 
     parser.add_argument("--format", "-f", type=str, required=True, choices=output_formats, 
                         help=f"Supported output formats.")
     parser.add_argument("input", type=str, choices=["-"], help="'-' for stdin")
     parser.add_argument("-o", type=str, choices=["-"], help="'-' for stdout")
+    parser.add_argument("--version", "-v", action="version", version=__version__, help="print WireViz version")
 
     args = parser.parse_args()
-    
+
     try:
+        # Capture stdout
+        old_stdout = sys.stdout
+        sys.stdout = io.StringIO()
+
         data = wv.parse(inp = sys.stdin.read(), return_types=args.format)
+
+        # Restore stdout
+        sys.stdout = old_stdout
+
         if isinstance(data, str):
             sys.stdout.write(data)
         elif isinstance(data, bytes):
             sys.stdout.buffer.write(data)
         else:
             raise ValueError("Unsupported data format")
+        sys.exit(0)
 
     except Exception as e:
-        sys.stderr.write(str(e))
+        sys.stderr.write(str(e))
+        sys.stderr.write("\n-----------\n")
+        sys.stderr.write(traceback.format_exc())
+        sys.exit(1)