ibmfixes.py

[sourcecode language=”python” wraplines=”false”]
# ibmfixes.py by Dave Brand, http://dbrand666.wordpress.com/
# version 0.7
#
# This module is a collection of fixes for Jython 2.1 especially as
# used by IBM’s WebSphere wsadmin utility. Import it early and often.
#
# Apologies for most of the constructs I’ve used in this file. Most
# of what we’re trying to accomplish here leans on dark details of the
# current wsadmin and Jython implementation. I’ve stuck catch-all’s
# around anything that I fear might change in future implementations.
# The theory is that future implementations won’t need the fixes and
# they should fail silently.
#
# Feel free to use it without understanding it. Read it and learn if
# you’re so inclined but don’t learn programmming style from it.
#
# The latest version can always be found at:
# http://dbrand666.wordpress.com/ibmfixes-py/

import __builtin__
import os, sys

# There isn’t much here that’s useful for Python, but let it pass anyway
try:
import java
except:
pass

# We’re going to be referencing the top-level frame in many of the fixes.
# Find it once.
topframe = sys._getframe()
up1frame = topframe.f_back
while topframe.f_back:
topframe = topframe.f_back

# Fix #1 (http://dbrand666.wordpress.com/fix1/)
#
# Fix for os.environ on Windows Servers post 2001.
#
# As of WebSphere 7.0, IBM is still shipping with Jython 2.1. That
# means it doesn’t know about any os.name’s which might have been
# added since 2001, which would include versions of Windows starting
# with Windows 2003. Without this, you’d see an error about /bin/sh
# when using os.environ and related functionality on Windows 2003 and
# later servers.
try:
import javaos
if javaos._osType == ‘posix’ and
java.lang.System.getProperty(‘os.name’).startswith(‘Windows’):
sys.registry.setProperty(‘python.os’, ‘nt’)
reload(javaos)
except:
pass
# End fix #1

# Fix #2 (http://dbrand666.wordpress.com/fix2/)
#
# Allow the Admin* "modules" to be import’ed.
#
# The Admin* modules aren’t actually available as modules. You can
# use them in the script invoked directly by wsadmin, but various
# workarounds are required if you want to be able to use them in
# imported modules. All of the fixes I’ve seen published depend on
# inserting a block of code into the top level script. I wanted
# something less invasive so I came up with this.
try:
for module in ‘AdminApp’, ‘AdminConfig’, ‘AdminControl’, ‘AdminTask’, ‘Help’:
if topframe.f_globals.has_key(module):
sys.modules[module] = topframe.f_globals[module]
except:
pass
# End fix #2

# Fix #3 (http://dbrand666.wordpress.com/fix3/)
#
# True and False
#
# This one’s trivial so why not do it? Define a bool type and True
# and False (but only if they’re not already defined).
try:
True and False
except NameError:
class bool(type(1)):
def __init__(self, val = 0):
if val:
type(1).__init__(self, 1)
else:
type(1).__init__(self, 0)
def __repr__(self):
if self:
return ‘True’
else:
return ‘False’

__str__ = __repr__

__builtin__.bool = bool
__builtin__.False = bool(0)
__builtin__.True = bool(1)
# End fix #3

# Fix #4 (http://dbrand666.wordpress.com/fix4/)
#
# __name__ of top level script should be __main__
#
# When running a script in wsadmin, the top-level __name__ is "main"
# instead of "__main__". This will fix that.
#
# Since this could potentially break an existing main and since it’s
# really only of interest to main, we only do this only if we’re
# imported directly the top frame.
try:
if up1frame == topframe and topframe.f_locals[‘__name__’] == ‘main’:
topframe.f_locals[‘__name__’] = ‘__main__’
except:
pass
# End fix #4

# Fix #5 (http://dbrand666.wordpress.com/fix5/)
#
# wsadmin’s argument list, sys.argv[] is missing the script name
#
# Another incompatibility is that in wsadmin, sys.argv contains only
# the command line arguments. Python passes in the script name as
# sys.argv[0] and the arguments as argv[1…]. Moving the arguments
# over is easy enough but we don’t have a good way to recover the
# script name. The full command line is available as a string in
# IBM_JAVA_COMMAND_LINE (sort of) but it has a lot of "stuff"
# prepended to it. Also, the script name isn’t quoted, so if it
# contains spaces there’s really no way to know where it ends. We
# try our best.
#
# Might as well assign the name to __file__ as well while we have it
# (another thing wsadmin is missing).
#
# Since this could potentially break an existing main and since it’s
# really only of interest to main, we only do this only if we’re
# imported directly from the top frame.
mainfile = None
cmdline = os.environ.get(‘IBM_JAVA_COMMAND_LINE’)
if cmdline:
beg = 0
end = len(cmdline)
# Throw away everything after the ‘–‘, if present.
dashdash = cmdline.find(‘–‘, beg, end)
if dashdash >= 0:
end = dashdash
# If we can’t find a filename, just use a "-"
mainfile = ‘-‘
dashf = cmdline.rfind(‘ -f ‘, beg, end)
if dashf:
# Grab everything from after the "-f" to the following space.
beg = dashf + 4
space = cmdline.find(‘ ‘, beg, end)
if space >= 0:
end = space
mainfile = cmdline[beg:end]
if up1frame == topframe and not topframe.f_globals.get(‘__file__’):
sys.argv[:0] = [ mainfile ]
topframe.f_globals[‘__file__’] = mainfile
# End fix #5

# Fix #6 (http://dbrand666.wordpress.com/fix6/)
#
# wsadmin doesn’t add the script’s path to the import search path
#
# Python adds the script directory to sys.path. wsadmin doesn’t. Now
# that we have the script path (hopefully) from fix 5, let’s prepend
# it to the path.
#
# On the flip side, wsadmin adds the current directory to the path;
# python doesn’t. Jython doesn’t either but it seems to search the
# current directory anyway. Should we add it to Python’s path? It
# might make it more compatible but it seems like a potential
# stumbling block and a security risk. Let’s not.
#
# P.S. Too bad this won’t help you find ibmfixes.py itself.

if mainfile:
mainpath = os.path.dirname(mainfile)
if mainpath:
sys.path[:0] = [ os.path.abspath(mainpath) ]
# End fix #6

# Fix #7
#
# sorted()
#
# This isn’t really a fix, but I like to be able to sort a list
# without modifying it. This just implements the sorted function as
# introduced in Python 2.4.

import copy
try:
sorted
except NameError:
def sorted(iterable):
ll = copy.copy(iterable)
ll.sort()
return ll
__builtin__.sorted = sorted
# End fix #7
[/sourcecode]