[stdlib-sig] quoting arguments for command-line evaluation

[Bill Janssen]

C. Titus Brown <ctb at msu.edu> wrote:

> On Mon, May 24, 2010 at 07:46:32AM -0700, Bill Janssen wrote:
> > I'm kind of surprised to see that the subprocess module doesn't have a
> > documented function for calling to properly quote command-line
> > arguments.  Nor does it seem to do so automatically -- at least on Unix.
> 
> Bill, I may be about to reveal my profound ignorance here, but...
> 
> do you need to quote arguments passed as a list on UNIX?  My impression
> was that if shell=False, then it wasn't needed.

Yes, that's right.  You need to quote them only if you are passing a
whole command line to be evaluated as a shell, as with os.system() or
shell=True and args a string with subprocess.  I think subprocess gets
all this more or less right.

In my case, I was building up a command line to pass as a single string
to subprocess, and needed a way to quote the args explicitly.  That's
why I went looking at this.

Bill