Add command line interface for file parsing and conversion

README.md

@@ -252,6 +252,24 @@ print(urdf_string)
 
 </details>
 
+## Command Line Interface
+
+ROD provides a command line interface (CLI) for processing robot description files. You can use the CLI to display file attributes or convert files between URDF and SDF formats.
+
+### Usage
+
+- Display the attributes of an SDF file:
+
+```sh
+rod --file /path/to/file.sdf --show
+```
+
+- Convert an SDF file to URDF:
+
+```sh
+rod --file /path/to/file.sdf -o /path/to/file.urdf
+```
+
 ## Similar projects
 
 - https://github.com/gazebosim/sdformat

src/rod/__main__.py

@@ -0,0 +1,115 @@
+import argparse
+import importlib.metadata
+import logging
+import sys
+
+from rod import logging as rodlogging
+
+
+def main() -> None:
+    """
+    Main function of the ROD command line interface.
+    """
+    parser = argparse.ArgumentParser(
+        prog="rod",
+        description="ROD: The ultimate Python tool for RObot Descriptions processing.",
+        usage="%(prog)s [options] file",
+    )
+
+    # Version.
+    parser.add_argument(
+        "-V",
+        "--version",
+        action="version",
+        version=f"%(prog)s {importlib.metadata.version('rod')}",
+    )
+
+    # Verbose output.
+    parser.add_argument(
+        "-vv",
+        "--verbose",
+        action="store_true",
+        help="enable verbose output.",
+    )
+
+    # File to parse.
+    parser.add_argument(
+        "-f",
+        "--file",
+        type=str,
+        help="path to the file to parse.",
+        required=False,
+    )
+
+    # Option to display the parser file attributes.
+    parser.add_argument(
+        "-s",
+        "--show",
+        action="store_true",
+        help="show the robot model attributes.",
+    )
+
+    # Option to output a URDF or SDF file.
+    parser.add_argument(
+        "-o",
+        "--output",
+        type=str,
+        help="Output file path.",
+    )
+
+    args = parser.parse_args()
+
+    log_level = logging.DEBUG if args.verbose else logging.INFO
+
+    logging.basicConfig(level=log_level)
+
+    from rod.urdf.exporter import UrdfExporter
+
+    # Ensure file argument is provided if output or `show` is specified.
+    if not args.file and (args.output or args.show):
+        parser.error(
+            "The `--file` argument is required when using `--output` or `--show`."
+        )
+
+    # Show the file attributes if no output file is specified.
+    if args.file and not (args.output or args.show):
+        args.show = True
+
+    # Display the parsed file attributes.
+    if args.file:
+        from rod import Sdf
+
+        try:
+            sdf = Sdf.load(sdf=args.file)
+        except Exception as e:
+            rodlogging.error(f"Error loading file: {e}")
+            sys.exit(1)
+
+    if args.show:
+        print(sdf.to_string())
+
+    # Output the URDF or SDF file.
+    if args.output:
+
+        try:
+            if args.output.endswith(".urdf"):
+                with open(args.output, "w") as file:
+                    file.write(UrdfExporter(pretty=True).to_urdf_string(sdf=sdf))
+
+            elif args.output.endswith(".sdf"):
+                with open(args.output, "w") as file:
+                    file.write(sdf.serialize(pretty=True))
+
+            else:
+                rodlogging.error(
+                    f"Unsupported output file extension for '{args.output}'. Supported extensions are '.urdf' and '.sdf'."
+                )
+                sys.exit(1)
+
+        except Exception as e:
+            rodlogging.exception(f"Error writing output file: {e}")
+            sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()