Help replacing os.system call with subprocess call

[David Harrison]

On 07/04/2008, David Harrison <dave.l.harrison at gmail.com> wrote:
> On 07/04/2008, David Pratt <fairwinds at eastlink.ca> wrote:
>  > Hi. I am trying to replace a system call with a subprocess call. I have
>  >  tried subprocess.Popen and subprocess.call with but have not been
>  >  successful. The command line would be:
>  >
>  >  svnadmin dump /my/repository > svndump.db
>  >
>  >  This is what I am using currently:
>  >
>  >  os.system('svnadmin dump %s > %s' % (svn_dir,
>  >      os.path.join(backup_dir, 'svndump.db')))
>  >
>  >  Many thanks.
>  >
>  > --
>  >  http://mail.python.org/mailman/listinfo/python-list
>  >
>
>
> Hey David,
>
>  Your probably want something like the following (code untested and off
>  the cuff ;-) )
>
>  Cheers
>  Dave
>
>  ---
>
>  import subprocess
>
>  p = subprocess.Popen(
>     [ "svnadmin", "dump" ],
>     stdin=subprocess.PIPE,
>     stdout=subprocess.PIPE,
>     stderr=subprocess.PIPE,
>     close_fds=True
>  )
>  (child_stdout, child_stdin) = (p.stdout, p.stdin)
>
>  f = open('svndump.db')
>  f.write(child_stdout.read())
>  f.close()

My inner pendant kicked in so I tested the code using [ 'ls', '-lha' ]
and found that the file object should be f = open('svndump.db', 'w')
instead :-)