1 files changed, 58 insertions, 5 deletions
diff --git a/src/setuptools_scm/__main__.py b/src/setuptools_scm/__main__.py
index f3377b0..ef64819 100644
--- a/src/setuptools_scm/__main__.py
+++ b/src/setuptools_scm/__main__.py
@@ -1,15 +1,68 @@
-import sys
+import argparse
+import os
+import warnings
 
-from setuptools_scm import get_version
+from setuptools_scm import _get_version
+from setuptools_scm.config import Configuration
+from setuptools_scm.discover import walk_potential_roots
 from setuptools_scm.integration import find_files
 
 
 def main() -> None:
-    print("Guessed Version", get_version())
-    if "ls" in sys.argv:
-        for fname in find_files("."):
+    opts = _get_cli_opts()
+    root = opts.root or "."
+
+    try:
+        pyproject = opts.config or _find_pyproject(root)
+        root = opts.root or os.path.relpath(os.path.dirname(pyproject))
+        config = Configuration.from_file(pyproject)
+        config.root = root
+    except (LookupError, FileNotFoundError) as ex:
+        # no pyproject.toml OR no [tool.setuptools_scm]
+        warnings.warn(f"{ex}. Using default configuration.")
+        config = Configuration(root)
+
+    print(_get_version(config))
+
+    if opts.command == "ls":
+        for fname in find_files(config.root):
             print(fname)
 
 
+def _get_cli_opts():
+    prog = "python -m setuptools_scm"
+    desc = "Print project version according to SCM metadata"
+    parser = argparse.ArgumentParser(prog, description=desc)
+    # By default, help for `--help` starts with lower case, so we keep the pattern:
+    parser.add_argument(
+        "-r",
+        "--root",
+        default=None,
+        help='directory managed by the SCM, default: inferred from config file, or "."',
+    )
+    parser.add_argument(
+        "-c",
+        "--config",
+        default=None,
+        metavar="PATH",
+        help="path to 'pyproject.toml' with setuptools_scm config, "
+        "default: looked up in the current or parent directories",
+    )
+    sub = parser.add_subparsers(title="extra commands", dest="command", metavar="")
+    # We avoid `metavar` to prevent printing repetitive information
+    desc = "List files managed by the SCM"
+    sub.add_parser("ls", help=desc[0].lower() + desc[1:], description=desc)
+    return parser.parse_args()
+
+
+def _find_pyproject(parent):
+    for directory in walk_potential_roots(os.path.abspath(parent)):
+        pyproject = os.path.join(directory, "pyproject.toml")
+        if os.path.exists(pyproject):
+            return pyproject
+
+    raise FileNotFoundError("'pyproject.toml' was not found")
+
+
 if __name__ == "__main__":
     main()