show-bencodex

Author: dahlia

CHANGES.rst

@@ -8,6 +8,7 @@ To be released.
 
 - Python 3.5 and 3.6 are no more supported.  Instead, Python 3.8, 3.9, and 3.10
   are now officially supported.
+- Added ``show-bencodex``, a CLI program.
 
 
 Version 1.0.1

README.rst

@@ -37,6 +37,19 @@ b'du3:agei30eu4:nameu8:Jane Doeu11:nationalitylu2:BRu2:USee'
 {'age': 30, 'name': 'Jane Doe', 'nationality': ['BR', 'US']}
 
 
+Debug-friendly formatter
+------------------------
+
+The package also provides a CLI program named ``show-bencodex``, which shows
+the given Bencodex data file (or data from the stdin) in the debug-friendly
+format:
+
+.. code:: console
+
+   $ show-bencodex bencodex.dat
+   $ cat bencodex.dat | show-bencodex
+
+
 License
 -------
 

bencodex/cli.py

@@ -0,0 +1,63 @@
+import argparse
+import io
+import pprint
+import re
+import shutil
+import sys
+from typing import Optional
+
+from bencodex import load
+
+__all__ = 'main',
+
+parser = argparse.ArgumentParser(
+    description='Debug-friendly Bencodex formatter',
+)
+parser.add_argument(
+    'file',
+    metavar='FILE',
+    nargs='?',
+    help='the path of the Bencodex file to show.  if omitted (default) it '
+         'expects the Bencodex data from the standard input'
+)
+parser.add_argument(
+    '-x', '--hex-input',
+    action='store_true',
+    default=False,
+    help='expects the input data is not binary, but hexadecimal text'
+)
+
+
+def read_input(path: Optional[str], hex: bool):
+    if path is None:
+        # Pipes are not seekable
+        if hex:
+            data = hex_to_bin(sys.stdin.read())
+        else:
+            data = sys.stdin.buffer.read()
+        return io.BytesIO(data)
+    elif hex:
+        with open(path, 'r') as f:
+            hex_data = f.read()
+        data = hex_to_bin(hex_data)
+        return io.BytesIO(data)
+    return open(path, 'rb')
+
+
+def hex_to_bin(hex: str) -> bytes:
+    return bytes.fromhex(re.sub(r'[\s.,:;_-]+', '', hex))
+
+
+def main() -> None:
+    args = parser.parse_args()
+    term_size = shutil.get_terminal_size()
+    with read_input(args.file, args.hex_input) as f:
+        tree = load(f)
+    try:
+        pprint.pprint(tree, width=term_size.columns, compact=True)
+    except KeyboardInterrupt:
+        raise SystemExit(130)
+
+
+if __name__ == '__main__':
+    main()

setup.cfg

@@ -34,3 +34,7 @@ bencodex =
     spec/testsuite/*.dat
     spec/testsuite/*.yaml
     spec/testsuite/*.yml
+
+[options.entry_points]
+console_scripts =
+    show-bencodex = bencodex.cli:main

tox.ini

@@ -7,8 +7,11 @@ deps =
     flake8 >= 3.6.0
     flake8-import-order-spoqa >= 1.5.0
     PyYAML ~= 3.13
+allowlist_externals =
+    echo
 commands =
     python setup.py test
+    echo 6475383a434c4920746573747465 | show-bencodex -x
     flake8
 
 [testenv:mypy]