lnaddr: make it possible to use lnaddr to decode arbitrary invoices on the cmd line

electrum/lnaddr.py

@@ -402,3 +402,10 @@ class SerializableKey:
         self.pubkey = pubkey
     def serialize(self):
         return self.pubkey.get_public_key_bytes(True)
+
+if __name__ == '__main__':
+    # run using
+    # python3 -m electrum.lnaddr <invoice> <expected hrp>
+    # python3 -m electrum.lnaddr lntb1n1pdlcakepp5e7rn0knl0gm46qqp9eqdsza2c942d8pjqnwa5903n39zu28sgk3sdq423jhxapqv3hkuct5d9hkucqp2rzjqwyx8nu2hygyvgc02cwdtvuxe0lcxz06qt3lpsldzcdr46my5epmj9vk9sqqqlcqqqqqqqlgqqqqqqgqjqdhnmkgahfaynuhe9md8k49xhxuatnv6jckfmsjq8maxta2l0trh5sdrqlyjlwutdnpd5gwmdnyytsl9q0dj6g08jacvthtpeg383k0sq542rz2 tb1n
+    import sys
+    print(lndecode(sys.argv[1], expected_hrp=sys.argv[2]))