[PATCH 0/2] replace os.system and os.popen with subbprocess module

[Robert Yang <liezhi.yang@windriver.com>]

Replace os.popen and os.system with subprocess.Popen and
subprocess.call, since the older functions would fail (more or less) if
the executed program cannot be found, this would cause potential errors
since we don't know whether the problem executed well or not.

For the performance issue, I've done the testing before the patches and
after with the oe-core layer (also the oe-core have applied the similar
patches):

# The sources are on local disk

1) Before applied these pacthes to bitbake and similar patches to oe-core:
$ time bitbake core-image-sato
real    177m50.723s
user    436m1.551s
sys     71m29.588s

2) After applied the pathes:
$ time bitbake core-image-sato
real    176m26.194s
user    436m7.931s
sys     71m1.994s

After applied these patches, the time has reduced 84 seconds, this is
very slight, I think that we can assume this is just a deviation, it
doesn't cause performance problems.

// Robert

The following changes since commit 12b4543ac9f54c0db0ee4a7ee546a71946a051f8:

  classes/rootfs_*: fix splitting package dependency strings (2012-05-13 20:09:56 +0100)

are available in the git repository at:
  git://git.pokylinux.org/poky-contrib robert/subprocess
  http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=robert/subprocess

Robert Yang (2):
  replace os.system with subprocess.call
  replace os.popen with subprocess.Popen

 bitbake/lib/bb/fetch2/perforce.py            |    9 +++++----
 bitbake/lib/bb/fetch2/svk.py                 |    3 ++-
 bitbake/lib/bb/shell.py                      |    6 +++---
 bitbake/lib/bb/ui/crumbs/builddetailspage.py |    3 ++-
 bitbake/lib/bb/ui/crumbs/hig.py              |    2 +-
 bitbake/lib/bb/ui/crumbs/imagedetailspage.py |    3 ++-
 bitbake/lib/bb/ui/ncurses.py                 |    4 ++--
 7 files changed, 17 insertions(+), 13 deletions(-)