bin/auto-classify

 #!/usr/bin/env python3
+#
+# Copyright © 2020-2021 Chris Lamb <lamby@debian.org>
+#
+# diffoscope is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# diffoscope is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with diffoscope.  If not, see <https://www.gnu.org/licenses/>.
 
 import re
+import sys
 import json
+import click
 import fileinput
 
 
+@click.command()
+def main():
+    """
+    Takes the output from `diffoscope --json=X` and attempts to guess which
+    issue(s) the package is affected by. For example:
+
+        $ diffoscope --json=output.json a.dsc b.dsc
+        $ bin/auto-classify output.json
+        build_path_captured_by_octave
+        $
+
+    If no arguments are provided, the JSON is read from standard input so
+    you can pipe it in. For example:
+
+        $ diffoscope --json=- a.dsc b.dsc | bin/auto-classify
+        build_path_captured_by_octave
+    """
+
+    raw = "".join(fileinput.input())
+
+    for x in walk_json(json.loads(raw)):
+        print(x)
+
+
 def walk_json(elem):
     if isinstance(elem, list):
         for x in elem:
@@ -121,7 +162,4 @@ def walk_json(elem):
 
 
 if __name__ == "__main__":
-    raw = "".join(fileinput.input())
-
-    for x in walk_json(json.loads(raw)):
-        print(x)
+    sys.exit(main())