X-Git-Url: https://arthur.barton.de/gitweb/?a=blobdiff_plain;f=main.py;h=c0679e32919fa0a6b721ce70bd4eed8add70dcc4;hb=579409999b16b296bfb75b544179bbf4e9213257;hp=154c5dc393b8d7493d037e77aec2c29f69a55bdd;hpb=80addc3f11e41101ed3a30aa17d4d8741d5592b9;p=bup.git

diff --git a/main.py b/main.py
index 154c5dc..c0679e3 100755
--- a/main.py
+++ b/main.py
@@ -5,9 +5,15 @@ exec "$bup_python" "$0" ${1+"$@"}
 """
 # end of bup preamble
 
-from __future__ import absolute_import
+from __future__ import absolute_import, print_function
 import errno, re, sys, os, subprocess, signal, getopt
 
+if sys.version_info[0] != 2 \
+   and not os.environ.get('BUP_ALLOW_UNEXPECTED_PYTHON_VERSION') == 'true':
+    print('error: bup may crash with python versions other than 2, or eat your data',
+          file=sys.stderr)
+    sys.exit(2)
+
 from subprocess import PIPE
 from sys import stderr, stdout
 import select
@@ -169,7 +175,8 @@ def print_clean_line(dest, content, width, sep=None):
     os.write(dest, content)
     if len(content) < width:
         os.write(dest, ' ' * (width - len(content)))
-    os.write(dest, sep)
+    if sep:
+        os.write(dest, sep)
 
 def filter_output(src_out, src_err, dest_out, dest_err):
     """Transfer data from src_out to dest_out and src_err to dest_err via