[Python-Dev] Re: subprocess - updated popen5 module (original) (raw)

Jason Lunz lunz at falooley.org
Sat Oct 9 15:54:22 CEST 2004

astrand at lysator.liu.se said:

...which is slighly nicer. The drawback with callv is that it does not allow specifying the program and it's arguments as a whitespace-separated string: The entire (first) string would be intepreted as the executable. So, you cannot do:

subprocess.callv("somewindowsprog.exe some strange command line") because then the system would try to execute a program called "somewindowsprog.exe some strange command line", which doesn't exist. You cannot do this either: subprocess.callv("somewindowsprog.exe", "some", "strange", "command", "line") ...if somewindowsprog.exe doesn't use the MS C runtime argument rules.

I'm not sure I understand what the MSC runtime has to do with the naming of call/callv. Your examples don't work with call either, right? Their call() equivalents:

subprocess.call(["somewindowsprog.exe some strange command line"])
subprocess.call(["somewindowsprog.exe", "some", "strange", "command", "line"])

are just as broken, no?

Overall, I agree that callv() is superfluous. In my programming, I always end up using the "v" variants of exec functions, because there's always something you do to the command line first, and it's easier to handle arguments as a list.

[The above paragraph makes my point: "I always use execv(), so we should drop subprocess.callv()?" The naming hurts my poor brain.]

Jason

More information about the Python-Dev mailing list