Re: [python-win32] does pipes.quote() work properly on Windows?
Bill Janssen wrote: I'm actually not passing file names. I'm passing argument strings, which may contain spaces, quotes, and other things. For instance, myprogram --title=That's the game! says Mike Hammer Brotsky --file=... myprogram is a Python program, and expects to get the whole --title argument as a single element of sys.argv. On Unix, I use arg = --title=%s % pipes.quote(title) to achieve that effect. What's the equivalent on Windows? Since cmd.exe also supports pipelines, I'd sort of expect it to do the right thing on Windows, too. Ah, foolish mortal. The problem with Windows is that, as I said, there is no central command-line parser, so there is no single set of rules. Cmd.exe does not parse the command line. Cmd.exe does not create argc/argv. Cmd.exe just passes the whole command line as a string. For C programs, the C run-time library will crack that string into argc/argv. Python on Windows has its own parser. If you are creating a list of arguments to pass AS A LIST, then no quoting is necessary. If you intend to mash them together into a single string, then I'm afraid you will need to experiment. -- Tim Roberts, t...@probo.com Providenza Boekelheide, Inc. ___ python-win32 mailing list python-win32@python.org http://mail.python.org/mailman/listinfo/python-win32
Re: [python-win32] does pipes.quote() work properly on Windows?
Tim Roberts t...@probo.com wrote: Bill Janssen wrote: I'm actually not passing file names. I'm passing argument strings, which may contain spaces, quotes, and other things. For instance, myprogram --title=That's the game! says Mike Hammer Brotsky --file=... myprogram is a Python program, and expects to get the whole --title argument as a single element of sys.argv. On Unix, I use arg = --title=%s % pipes.quote(title) to achieve that effect. What's the equivalent on Windows? Since cmd.exe also supports pipelines, I'd sort of expect it to do the right thing on Windows, too. Ah, foolish mortal. Quixotic, perhaps, to attempt to achieve consistency on Windows... Actually, my last sentence there was more about, Why doesn't the pipes module also work on Windows?, than it was about quoting. The problem with Windows is that, as I said, there is no central command-line parser, so there is no single set of rules. Cmd.exe does not parse the command line. Cmd.exe does not create argc/argv. Cmd.exe just passes the whole command line as a string. For C programs, the C run-time library will crack that string into argc/argv. Python on Windows has its own parser. The subprocess module has an idea of how it should work. Whether or not it's correct is a different matter. So, is the algorithm the same for the visual studio C runtime's parser, and Python's parser? I'd expect that, since CPython is a C program that uses VS C. If so, I'd be happy to settle for that standard. The algorithm in the subprocess module is documented thusly: Translate a sequence of arguments into a command line string, using the same rules as the MS C runtime: 1) Arguments are delimited by white space, which is either a space or a tab. 2) A string surrounded by double quotation marks is interpreted as a single argument, regardless of white space or pipe characters contained within. A quoted string can be embedded in an argument. 3) A double quotation mark preceded by a backslash is interpreted as a literal double quotation mark. 4) Backslashes are interpreted literally, unless they immediately precede a double quotation mark. 5) If backslashes immediately precede a double quotation mark, every pair of backslashes is interpreted as a literal backslash. If the number of backslashes is odd, the last backslash escapes the next double quotation mark as described in rule 3. # See # http://msdn.microsoft.com/en-us/library/17w5ykft.aspx # or search http://msdn.microsoft.com for # Parsing C++ Command-Line Arguments Bill ___ python-win32 mailing list python-win32@python.org http://mail.python.org/mailman/listinfo/python-win32
Re: [python-win32] does pipes.quote() work properly on Windows?
On Fri, May 21, 2010 at 15:03, Bill Janssen jans...@parc.com wrote: Anyone know if the quote() function in the pipes module does the right thing for cmd.exe pipes? If not, what is the right thing? twisted.python.win32 has a couple functions that try very hard to get the quoting right. http://twistedmatrix.com/documents/current/api/twisted.python.win32.html#quoteArguments ___ python-win32 mailing list python-win32@python.org http://mail.python.org/mailman/listinfo/python-win32
Re: [python-win32] does pipes.quote() work properly on Windows?
Bill Janssen wrote: myprogram --title=That's the game! says Mike Hammer Brotsky --file=... Since cmd.exe also supports pipelines, I'd sort of expect it to do the right thing on Windows, too. Don't know about later versions, but in Python 2.5 the pipes module is listed under Unix specific services, so I guess it was never designed with Windows in mind. The reason it fails on Windows is that it assumes single quotes can be used to quote a string containing double quotes. But Windows usually requires double quotes around arguments, so you will have to escape the inner quotes: --title=That's the game! says Mike \Hammer\ Brotsky A quick test suggests that this will work, at least in the case where the program being passed the args is a Python program. -- Greg ___ python-win32 mailing list python-win32@python.org http://mail.python.org/mailman/listinfo/python-win32
Re: [python-win32] does pipes.quote() work properly on Windows?
Bill Janssen wrote: Anyone know if the quote() function in the pipes module does the right thing for cmd.exe pipes? No, it doesn't. It uses sh rules, which aren't the same. If not, what is the right thing? Unfortunately, command line parsing in Windows is not centralized in the shell. To satisfy cmd.exe, you can safely surround each file name in double quotes. Whether the application knows how to handle that or not is up to the application (although most do it correctly). Remember that this is only necessary when passing names to the command shell. The Windows APIs don't want the quotes. -- Tim Roberts, t...@probo.com Providenza Boekelheide, Inc. ___ python-win32 mailing list python-win32@python.org http://mail.python.org/mailman/listinfo/python-win32
Re: [python-win32] does pipes.quote() work properly on Windows?
Tim Roberts t...@probo.com wrote: Bill Janssen wrote: Anyone know if the quote() function in the pipes module does the right thing for cmd.exe pipes? No, it doesn't. It uses sh rules, which aren't the same. If not, what is the right thing? Unfortunately, command line parsing in Windows is not centralized in the shell. To satisfy cmd.exe, you can safely surround each file name in double quotes. Whether the application knows how to handle that or not is up to the application (although most do it correctly). Remember that this is only necessary when passing names to the command shell. The Windows APIs don't want the quotes. I'm actually not passing file names. I'm passing argument strings, which may contain spaces, quotes, and other things. For instance, myprogram --title=That's the game! says Mike Hammer Brotsky --file=... myprogram is a Python program, and expects to get the whole --title argument as a single element of sys.argv. On Unix, I use arg = --title=%s % pipes.quote(title) to achieve that effect. What's the equivalent on Windows? Since cmd.exe also supports pipelines, I'd sort of expect it to do the right thing on Windows, too. Bill ___ python-win32 mailing list python-win32@python.org http://mail.python.org/mailman/listinfo/python-win32
