Can we pass some arguments to system("cmdline ")?

[Didier C]

Hi!
I was wondering if we can pass some arguments to system("cmdline ")?

E.g in Perl, we can do something like:

$dir="/home/cypher";

system("ls $dir");

which would instruct Perl to do an "ls /home/cypher"

But in python, doing something like

dir="/home/cypher"
system("ls dir")

would cause python to execute "ls dir" where "dir" might not exist at
all! Is there a way to reproduce the same thing in Python?

Thanks for any insights.

cheers,
Didier.

[Qiangning Hong]

Didier C wrote:

Hi!
I was wondering if we can pass some arguments to system("cmdline ")?

E.g in Perl, we can do something like:

$dir="/home/cypher";

system("ls $dir");

which would instruct Perl to do an "ls /home/cypher"

But in python, doing something like

dir="/home/cypher"
system("ls dir")

would cause python to execute "ls dir" where "dir" might not exist at
all! Is there a way to reproduce the same thing in Python?

Thanks for any insights.

cheers,
Didier.

You should use something like this:

dir = "/home/cypher"
system("ls %s" % dir)

--
Qiangning Hong

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[Andreas Kostyrka]

On Sun, Jun 19, 2005 at 11:12:05PM -0700, Didier C wrote:

Hi!
I was wondering if we can pass some arguments to system("cmdline ")?

E.g in Perl, we can do something like:

$dir="/home/cypher";

system("ls $dir");

which would instruct Perl to do an "ls /home/cypher"

But in python, doing something like

dir="/home/cypher"
system("ls dir")

system("ls %(dir)s" % locals())
system("ls %s" % dir)
system("ls %(name)s" % dict(name=dir)

But you should consider if you really really want to do this.
What happens when " " in dir?
What happens when dir == "; rm -Rf /"

Andreas

[Leif K-Brooks]

Didier C wrote:

E.g in Perl, we can do something like:

$dir="/home/cypher";

system("ls $dir");

Is there a way to reproduce the same thing in Python?

system("ls %s" % dir)

But you should really be using subprocess for security (so that if
dir=="/home/foo; rm -rf /" nothing bad will happen):

import subprocess
subprocess.Pope n(['ls', dir])

[Didier Casse]

Thanks all for the reply. I'll try out those things out. :)

Cheers,
Didier.
Leif K-Brooks a écrit :

Didier C wrote:

E.g in Perl, we can do something like:

$dir="/home/cypher";

system("ls $dir");

Is there a way to reproduce the same thing in Python?

system("ls %s" % dir)

But you should really be using subprocess for security (so that if
dir=="/home/foo; rm -rf /" nothing bad will happen):

import subprocess
subprocess.Pope n(['ls', dir])

[Piet van Oostrum]

>>>>> "Didier Casse" <el********@gma il.com> (DC) wrote:

DC> Thanks all for the reply. I'll try out those things out. :)

But don't try the following

> system("ls $dir"); with dir=="/home/foo; rm -rf /"

--
Piet van Oostrum <pi**@cs.uu.n l>
URL: http://www.cs.uu.nl/~piet [PGP]
Private email: pi**@vanoostrum .org