Add trailing whitespace fixer.

pre_commit_hooks/trailing_whitespace_fixer.py

@@ -0,0 +1,30 @@
+
+import argparse
+import sys
+from plumbum import local
+
+
+def fix_trailing_whitespace(argv):
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    bad_whitespace_files = filter(bool, local['grep'][
+        ('-l', '[[:space:]]$') + tuple(args.filenames)
+    ](retcode=None).splitlines())
+
+    if bad_whitespace_files:
+        for bad_whitespace_file in bad_whitespace_files:
+            print 'Fixing {0}'.format(bad_whitespace_file)
+            local['sed']['-i', '-e', 's/[[:space:]]*$//', bad_whitespace_file]()
+        return 1
+    else:
+        return 0
+
+
+def entry():
+    fix_trailing_whitespace(sys.argv[1:])
+
+
+if __name__ == '__main__':
+    sys.exit(entry())