Sanitize Print (#1135)

* sanitize strings with shell control characters

* netlib: add utilities to safe-print bytes

* escaped str: add TODO for multi-byte chars

1 files changed, 28 insertions, 0 deletions

diff --git a/netlib/utils.py b/netlib/utils.py
index ebd192f3..be2701a0 100644
--- a/netlib/utils.py
+++ b/netlib/utils.py
@@ -431,3 +431,31 @@ def safe_subn(pattern, repl, target, *args, **kwargs):
         need a better solution that is aware of the actual content ecoding.
     """
     return re.subn(str(pattern), str(repl), target, *args, **kwargs)
+
+
+def bytes_to_escaped_str(data):
+    """
+    Take bytes and return a safe string that can be displayed to the user.
+    """
+    # TODO: We may want to support multi-byte characters without escaping them.
+    # One way to do would be calling .decode("utf8", "backslashreplace") first
+    # and then escaping UTF8 control chars (see clean_bin).
+
+    if not isinstance(data, bytes):
+        raise ValueError("data must be bytes")
+    return repr(data).lstrip("b")[1:-1]
+
+
+def escaped_str_to_bytes(data):
+    """
+    Take an escaped string and return the unescaped bytes equivalent.
+    """
+    if not isinstance(data, str):
+        raise ValueError("data must be str")
+
+    if six.PY2:
+        return data.decode("string-escape")
+
+    # This one is difficult - we use an undocumented Python API here
+    # as per http://stackoverflow.com/a/23151714/934719
+    return codecs.escape_decode(data)[0]