# # Copyright 2004 Apache Software Foundation  #  # Licensed under the Apache License, Version 2.0 (the "License"); you # may not use this file except in compliance with the License.  You # may obtain a copy of the License at # #      http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or # implied.  See the License for the specific language governing # permissions and limitations under the License. # # Originally developed by Gregory Trubetskoy. # # $Id: cgihandler.py 374268 2006-02-02 05:31:45Z nlehuen $import apacheimport impimport osimport sys# if threads are not available# create a functionless lock objecttry:    import threading    _lock = threading.Lock()except (ImportError, AttributeError):    class DummyLock:        def acquire(self):            pass        def release(self):            pass    _lock = DummyLock()# the next statement  deserves some explaining.# it seems that the standard os.environ object looses# memory if the environment is manipulated frequently. Since for# CGI you have to rebuild it for every request, your httpd will# grow rather fast. I am not exactly sure why it happens and if there# is a more sensible remedy, but this seems to work OK.os.environ = {}original = sys.modules.keys()# find out the standard library locationstdlib, x = os.path.split(os.__file__)def handler(req):    ### if you don't need indirect modules reloaded, comment out    ### code unitl ### end    # if there are any new modules since the import of this module,    # delete them.    for m in sys.modules.keys():        if m not in original:            # unless they are part of standard library            mod = sys.modules[m]            if hasattr(mod, "__file__"):                path, x = os.path.split(mod.__file__)                if path != stdlib:                    del sys.modules[m]    ### end    # get the filename of the script    if req.subprocess_env.has_key("script_filename"):        dir, file = os.path.split(req.subprocess_env["script_filename"])    else:        dir, file = os.path.split(req.filename)    module_name, ext = os.path.splitext(file)    _lock.acquire()    try:        try:            # The CGI spec requires us to set current working            # directory to that of the script. This is not            # thread safe, this is why we must obtain the lock.            cwd = os.getcwd()            os.chdir(dir)            # simulate cgi environment            env, si, so = apache.setup_cgi(req)            try:                # we do not search the pythonpath (security reasons)                fd, path, desc = imp.find_module(module_name, [dir])            except ImportError:                raise apache.SERVER_RETURN, apache.HTTP_NOT_FOUND            # this executes the module            imp.load_module(module_name, fd, path, desc)            return apache.OK        finally:            # unsimulate the cgi environment            apache.restore_nocgi(env, si, so)            try:                fd.close()            except: pass            os.chdir(cwd)    finally:        _lock.release()