On Sat, 16 Sep 2006 19:22:34 +0200, "\"Martin v. Löwis\"" <[EMAIL PROTECTED]> wrote: >The test suite currently (2.5) has two failures on Windows >if Python is installed into a directory with a space in it >(such as "Program Files"). The failing tests are test_popen >and test_cmd_line. > >The test_cmd_line failure is shallow: the test fails to properly >quote sys.executable when passing it to os.popen. I propose to >fix this in Python 2.5.1; see #1559413 > >test_popen is more tricky. This code has always failed AFAICT, >except that the test itself is a recent addition. The test tries >to pass the following command to os.popen > >"c:\Program Files\python25\python.exe" -c "import sys;print sys.version" > >For some reason, os.popen invokes doesn't directly start Python as >a new process, but install invokes > >cmd.exe /c "c:\Program Files\python25\python.exe" -c "import sys;print >sys.version" > >Can somebody remember what the reason is to invoke cmd.exe (or COMSPEC) >in os.popen?
I would guess it was done to force cmd.exe-style argument parsing in the subprocess, which is optional on Win32. > >In any case, cmd.exe fails to execute this, claiming that c:\Program >is not a valid executable. It would run > >cmd.exe /c "c:\Program Files\python25\python.exe" > >just fine, so apparently, the problem is with argument that have >multiple pairs of quotes. I found, through experimentation, that it >*will* accept > >cmd.exe /c ""c:\Program Files\python25\python.exe" -c "import sys;print >sys.version"" > >(i.e. doubling the quotes at the beginning and the end). I'm not quite >sure what algorithm cmd.exe uses for parsing, but it appears that >adding a pair of quotes works in all cases (at least those I could think >of). See # 1559298 You can find the quoting/dequoting rules used by cmd.exe documented on msdn: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclang/html/_pluslang_Parsing_C.2b2b_.Command.2d.Line_Arguments.asp Interpreting them is something of a challenge (my favorite part is how the examples imply that the final argument is automatically uppercased ;) Here is an attempted implementation of the quoting rules: http://twistedmatrix.com/trac/browser/trunk/twisted/python/win32.py#L41 Whether or not it is correct is probably a matter of discussion. If you find a more generally correct solution, I would certainly like to know about it. Jean-Paul _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
