How do I pass a variable to an external program

[Rigga]

Hi

I would like to pass a variable to an external program i.e.

os.system('cd $variable')

However this doesnt work, I cant figure it out, any ideas?

Cheers

Rigga

[Cameron Laird]

In article <sh************ ***@news-binary.blueyond er.co.uk>,
Rigga <Ri***@noemail. com> wrote:

Hi

I would like to pass a variable to an external program i.e.

os.system('c d $variable')

However this doesnt work, I cant figure it out, any ideas?

[Rigga]

Cameron Laird wrote:

In article <sh************ ***@news-binary.blueyond er.co.uk>,
Rigga <Ri***@noemail. com> wrote:

Hi

I would like to pass a variable to an external program i.e.

os.system(' cd $variable')

However this doesnt work, I cant figure it out, any ideas?

.
.
.
In the short term,
os.system('cd %s' % variable)
is probably what you think you want.

Wow thanks for the fast response that works a treat, now i just gotta find
out how you run more than one command on a line i.e.
os.system('cd %s' 'ls -lt')

[Cameron Laird]

In article <gu************ ***@news-binary.blueyond er.co.uk>,
Rigga <Ri***@noemail. com> wrote:

.
.
.
In the short term,
os.system('cd %s' % variable)
is probably what you think you want.

Wow thanks for the fast response that works a treat, now i just gotta find
out how you run more than one command on a line i.e.
os.system('c d %s' 'ls -lt')

os.system('cd %s; ls -lt' % variable)

To save even more time, visit <URL: http://
www.python.org/doc/current/tut/tut.html >.
--

Cameron Laird <cl****@phaseit .net>
Business: http://www.Phaseit.net

[Rigga]

Cameron Laird wrote:

In article <gu************ ***@news-binary.blueyond er.co.uk>,
Rigga <Ri***@noemail. com> wrote:

.
.
.
In the short term,
os.system('cd %s' % variable)
is probably what you think you want.

Wow thanks for the fast response that works a treat, now i just gotta find
out how you run more than one command on a line i.e.
os.system(' cd %s' 'ls -lt')

os.system('cd %s; ls -lt' % variable)

To save even more time, visit <URL: http://
www.python.org/doc/current/tut/tut.html >.

Thanks Cameron your help and patience has been appreciated.

Regards

Rigga

[Gerrit Holl]

Rigga wrote:

I would like to pass a variable to an external program i.e.
There are different possiblities to that.
os.system('cd $variable')
Note that this does nothing. 'cd' only has consequences for the
current process, since it is a change directory. If you want to
change your directory, you need os.chdir instead.
See also: help(os.chdir)
However this doesnt work, I cant figure it out, any ideas?

os.system is simply given a string, where spaces mark the different
arguments. You can put a variable into a string with several
methods:

s = "cd %s" % variable
s = "cd " + str(variable)
s = "cd +%(variable)s" % locals()

You can also call os.spawn instead of os.system. This way, you
pass a list or arguments (all strings) to the program, without
the problem that spaces may occur in one of them:

os.spawn("/bin/ls", ["ls", "/usr/local"])
See also: help(os.spawn)

Please look at the online documentation at python.org for more information
on string substitution, starting subprocceses, changing directories
and other things.

Gerrit.

--
121. If any one store corn in another man's house he shall pay him
storage at the rate of one gur for every five ka of corn per year.
-- 1780 BC, Hammurabi, Code of Law
--
Asperger Syndroom - een persoonlijke benadering:
http://people.nl.linux.org/~gerrit/
Kom in verzet tegen dit kabinet:
http://www.sp.nl/