From 0157f74a31adc1bd999ea5e5bc3a9c34af90b98c Mon Sep 17 00:00:00 2001

From: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>

Date: Thu, 2 Apr 2020 16:03:57 +0530

Subject: [PATCH] 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>

---

 daemon/targetclid | 15 +++++++++------

 1 file 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()

-- 

2.21.0