Fix StringIO/BytesIO stuck issue

We all know the way python3 handles strings is a bit different.

$ python2
Python 2.7.16 (default, Apr 30 2019, 15:54:43)
[GCC 9.0.1 20190312 (Red Hat 9.0.1-0.10)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import io
>>> s=io.BytesIO()
>>> s.write('hello')
5L
>>> s.getvalue()
'hello'
>>> s=io.StringIO()
>>> s.write('hello')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unicode argument expected, got 'str'
>>> s.write(u'hello')
5L
>>> s.getvalue()
u'hello'
>>>

$ python3
Python 3.6.8 (default, Dec  5 2019, 15:45:45)
[GCC 8.3.1 20191121 (Red Hat 8.3.1-5)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import io
>>> s=io.BytesIO()
>>> s.write('hello')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: a bytes-like object is required, not 'str'
>>> s.write(b'hello')
5
>>> s.getvalue()
b'hello'
>>> s=io.StringIO()
>>> s.write('hello')
5
>>> s.getvalue()
'hello'
>>>

The way Python2 and Python3 handles String and Bytes IO is different.
* In Python2 BytesIO() accepts text format syntax, and StringIO() expects unicodes
* While in Python3 StringIO() accepts text format syntax, and BytesIO() expects bytes like objects

I think the compatibility of using both the IO streams with python2 and python3 is compromised.

Hence this patch, uses BytesIO() and StringIO() based on python version.

Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>

1 files changed, 9 insertions, 6 deletions

diff --git a/daemon/targetclid b/daemon/targetclid
index d4c6562..5df6ca2 100755
--- a/daemon/targetclid
+++ b/daemon/targetclid
@@ -32,9 +32,13 @@ import struct
 import fcntl
 import signal
 import errno
-import io
 
 
+if sys.version_info < (3, 0):
+    from io import BytesIO as StringIO
+else:
+    from io import StringIO
+
 err = sys.stderr
 
 class TargetCLI:
@@ -154,24 +158,23 @@ class TargetCLI:
                 connection.close()
                 still_listen = False
             else:
-                self.con._stdout = self.con._stderr = f = io.BytesIO()
+                self.con._stdout = self.con._stderr = f = StringIO()
                 try:
                     # extract multiple commands delimited with '%'
                     list_data = data.decode().split('%')
                     for cmd in list_data:
                         self.shell.run_cmdline(cmd)
                 except Exception as e:
-                    print(str(e), file=f) # push error to stream
+                    print(str(e).encode(), file=f) # push error to stream
 
                 # Restore
                 self.con._stdout = self.con_stdout_
                 self.con._stderr = self.con_stderr_
-
-                output = f.getvalue()
+                output = f.getvalue().encode()
                 var = struct.pack('i', len(output))
                 connection.sendall(var) # length of string
                 if len(output):
-                    connection.sendall(output.encode()) # actual string
+                    connection.sendall(output) # actual string
 
                 f.close()