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RE: how to change os.popen4 to subprocess

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Replying to skyworld because I could not find the original message
from MRAB.

skyworld wrote:
> On Oct 27, 11:02 am, MRAB <pyt...@mrabarnett.plus.com> wrote:
> > On 2012-10-27 03:28, skyworld wrote:> Hi,
> >
> > > I'm new to python and I'm trying to porting some scripts from v0.96 to
> > > v2.0.1. A piece of code is like this:
> >
> > > cmd_h = os.popen4(env['SYSCMDLINE'])[1]
> >
> > > the system indicates the popen4 is deprecated and suggest to use
> > > subprocess. Can anybody tell me how to use subprocess in this case?
> > > and what does "[1]" here means?
> >
> > os.popen4 returns a tuple of (child_stdin, child_stdout_and_stderr).
> > The [1] gets the child_stdout_and_stderr member.
> >
> > Using the subprocess module:
> >
> > # Untested!
> > cmd_h = subprocess.Popen(env['SYSCMDLINE'], stdout=subprocess.PIPE,
> > stderr=subprocess.STDOUT, shell=True).stdout
> >
> > Explanation:
> >
> > The command line: env['SYSCMDLINE']
> >
> > Return stdout: stdout=subprocess.PIPE
> >
> > stderr should be combined with stdout: stderr=subprocess.STDOUT
> >
> > Let the shell parse the command line: shell=True
> 
> thanks
> --

I thought the usage of shell=True is usually discouraged? The 
subprocess documentation[0] should be helpful to figure it out.
"""
Warning: Invoking the system shell with shell=True can be a security 
hazard if combined with untrusted input. See the warning under 
Frequently Used Arguments for details.
"""

[0] http://docs.python.org/2/library/subprocess.html 


Ramit


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how to change os.popen4 to subprocess skyworld <chenyong20000@gmail.com> - 2012-10-26 19:28 -0700
  Re: how to change os.popen4 to subprocess MRAB <python@mrabarnett.plus.com> - 2012-10-27 04:02 +0100
    Re: how to change os.popen4 to subprocess skyworld <chenyong20000@gmail.com> - 2012-10-26 23:30 -0700
      RE: how to change os.popen4 to subprocess "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-10-30 14:47 +0000
  Re: how to change os.popen4 to subprocess Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-10-27 04:10 +0100

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