Fix zLinux (OS system Z) support

[Albert-Jan Roskam]

zLinux should be supported but I don't know how to tell this system apart from other Linux systems. Using sys.platform is not enough, probably. Please email me if you know more about this: "@".join(["fomcl", "yahoo" + "." + "com"])

[Albert-Jan Roskam]

Anderson P. from System z Linux LinkedIn group kindly helped me with this. Tested with Linux on System z virtual machine running RHEL 5.6 under z/VM, using Python 2.4.3 (#1, Dec 10 2010, 17:28:02), the result was "Linux, 64bit, s390x"

[GCC 4.1.2 20080704 (Red Hat 4.1.2-50)] on linux2
>>> import sys, platform, os
>>> print platform.system()
Linux
>>> print platform.architecture()
('64bit', 'ELF')
>>> print os.uname()
('Linux', 'SCCD01.zcenter.spo.ihost.com', '2.6.18-238.el5', '#1 SMP Sun Dec 19 14:27:28 EST 2010', 's390x') 
# Consider s390 for the 31-bit architecture and s390x for 64bits. 
# Note that the SPSS I/O libraries are for a 64-bit architecture
# Therefore, the following one-liner should do the trick:
is_zLinux =  sys.platform.lower().startswith("lin") and is_64bit and os.uname()[-1] == "s390x"

[Albert-Jan Roskam]

System z Linux can be recognized like this:

is_zLinux =  sys.platform.lower().startswith("lin") and is_64bit and os.uname()[-1] == "s390x"