Newbie Alert: subprocess.call

[Chris Rebert]

On Wed, May 19, 2010 at 7:27 PM, Carbon <nobrac at nospam.tampabay.rr.com> wrote:
> I am new to Python and am trying to write a GUI wrapper script in python
> 2.5 to get username and passwords from Linux users to send as options to
> run an app on a 2X terminal server. I came across the easygui module and
> its multpasswordbox function, which made popping a dialog box and storing
> the usernames very painless.
>
> However, subprocess.call as implemented below doesn't work. For some
> reason the "-s ts.mycompany.org:80" parameter is being interpreted
> differently by the application when sent from the python script than it
> does when sent from the BASH script below. The :80 is the default port so
> it isn't technically required, but the script doesn't work without it
> either.
>
> Any ideas where I should look? Is subprocess.call the best way to do what
> I want? Any advice would be most appreciated.
>
>
> Here's the broken bit:
>
> print "Reply was:", fieldValues
> print "Reply was:", fieldValues[0], fieldValues[1]
>
> subprocess.call(["/opt/2X/Client/bin/appserverclient", "-u fieldValues
> [0]", "-p fieldValues[1]", "-s ts.mycompany.org:80", "-d corp", "-S
> local", "-c 16", "-e 0xF", "-l 0x0409", "-a #1"])

RTFineM (http://docs.python.org/library/subprocess.html#subprocess.Popen
). Verbatim quote, emphasis mine:

>>> command_line = raw_input()
/bin/vikings -input eggs.txt -output "spam spam.txt" -cmd "echo '$MONEY'"
>>> args = shlex.split(command_line)
>>> print args
['/bin/vikings', '-input', 'eggs.txt', '-output', 'spam spam.txt',
'-cmd', "echo '$MONEY'"]
>>> p = subprocess.Popen(args) # Success!
***Note in particular that options (such as -input) and arguments
(such as eggs.txt) that are separated by whitespace in the shell go in
separate list elements***, while arguments that need quoting or
backslash escaping when used in the shell (such as filenames
containing spaces or the echo command shown above) are single list
elements.

Cheers,
Chris
--
http://blog.rebertia.com