diff --git a/larger-than b/larger-than
new file mode 100755
index 0000000..808c05d
--- /dev/null
+++ b/larger-than
@@ -0,0 +1,54 @@
+#!/usr/bin/python3
+import os
+import subprocess
+import sys
+import re
+
+import click
+
+
+def du(paths):
+    # Just using coreutils du, to have deduping, and the correct size
+    result = subprocess.check_output(["du", "-sc", "--block-size=1", *paths])
+    total_line = result.splitlines()[-1]
+    total_bytes, total_check = total_line.split(b"\t")
+    assert total_check == b"total"
+    return int(total_bytes)
+
+
+def interpret_prefixes(number, si=False):
+    # prefix as the "K" in "KB"
+    multiplier = 1000 if si else 1024
+
+    if m := re.match(r"^(?i:(\d+)([kmg])?)", number):
+        number, prefix = m.groups()
+    else:
+        raise ValueError("Can't interpret size")
+
+    number = int(number)
+    if prefix is not None:
+        prefix = prefix.lower()
+
+    exponent = {
+            None: 0,
+            "k": 1,
+            "m": 2,
+            "g": 3,
+            "t": 4,
+            }
+    return number * multiplier ** exponent[prefix]
+
+@click.command()
+@click.argument("threshold")
+@click.argument("paths", nargs=-1)
+def larger_than(threshold, paths):
+    """Check if disk usage of PATHS is larger than THRESHOLD"""
+    threshold = interpret_prefixes(threshold)
+    if du(paths) > threshold:
+        sys.exit(0)
+    else:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    larger_than()