There appears to be a problem with
packing/unpacking long (and int) values when sending
data from Windows to Linux.
I am not sure if it is a bug or just due to
incompatibleness. Normally we think of long as being 4
bytes. However, on Linux, it might be 8 bytes (in
Python).
Here are good results in Windows, packing and
unpacking a long:
$ python
Python 2.4.2 (#67, Sep 28 2005, 12:41:11) [MSC v.1310
32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for
more information.
>>> import struct
>>> p = struct.pack("L", 12345)
>>> p
'90\x00\x00'
>>> u = struct.unpack("L",p)
>>> u
(12345L,)
However, on Linux, I get slightly different results:
Python 2.4.1 (#1, May 16 2005, 15:15:14)
[GCC 4.0.0 20050512 (Red Hat 4.0.0-5)] on linux2
Type "help", "copyright", "credits" or "license" for
more information>>> import struct
>>> p = struct.pack("L", 12345)
>>> p
'90\x00\x00\x00\x00\x00\x00'
>>> u = struct.unpack("L",p)
>>> u
(12345L,)
This is annoying, because I want to be able to
send data from Windows to Linux (and vice-versa)
over a socket. I am new to Python, and the only
way I know of of doing that is by packing and
unpacking the data.
Please email me m.yanowitz@kearfott.com if this
isn't a bug or there is a known work-around for
this problem.
Thanks in advance:
Michael Yanowitz
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