Add shell parameter to allow running commands directly.

Add shell parameter to allow running commands directly.

For chromite, we often want to run shell commands directly instead of using the
array syntax currently accepted by RunCommand. This makes it easier to run
piped commands, for example.

BUG=chromium-os:6573
TEST=I'm using it in cros_build.

Change-Id: Ic846e257fec4e423b0253d06641eac232545f6f6

[davidjames, 2010-09-09 17:02:39]

Both of us are working on code that needs this feature, so I'm sending this
review to you.

[Tan Gao, 2010-09-09 17:19:26]

http://codereview.chromium.org/3323019/diff/1/2
File chromite/lib/cros_build_lib.py (right):

http://codereview.chromium.org/3323019/diff/1/2#newcode18
chromite/lib/cros_build_lib.py:18: cmd - cmd to run.  Should be input to
subprocess.POpen.  If a string,
s/POpen/Popen/

http://codereview.chromium.org/3323019/diff/1/2#newcode19
chromite/lib/cros_build_lib.py:19: converted to an array using split().
urr, where's the string-to-array conversion?

http://codereview.chromium.org/3323019/diff/1/2#newcode29
chromite/lib/cros_build_lib.py:29: cwd must point to the scripts directory.
please add docstring for "shell" here

http://codereview.chromium.org/3323019/diff/1/2#newcode47
chromite/lib/cros_build_lib.py:47: if enter_chroot: cmd = './enter_chroot.sh --
' + cmd
"cmd" here is a string and in case of shell=True, it's a list?? i'm confused
>__<

[sosa, 2010-09-09 17:20:16]

http://codereview.chromium.org/3323019/diff/1/2
File chromite/lib/cros_build_lib.py (right):

http://codereview.chromium.org/3323019/diff/1/2#newcode43
chromite/lib/cros_build_lib.py:43: if shell:
Since you are using shell to determine whether or not to interpret the cmd as a
string, why not just actually check to see if it is a string i.e. instanceof

[davidjames, 2010-09-09 17:30:28]

http://codereview.chromium.org/3323019/diff/1/2
File chromite/lib/cros_build_lib.py (right):

http://codereview.chromium.org/3323019/diff/1/2#newcode18
chromite/lib/cros_build_lib.py:18: cmd - cmd to run.  Should be input to
subprocess.POpen.  If a string,
On 2010/09/09 17:19:26, Tan Gao wrote:
> s/POpen/Popen/

Done.

http://codereview.chromium.org/3323019/diff/1/2#newcode19
chromite/lib/cros_build_lib.py:19: converted to an array using split().
On 2010/09/09 17:19:26, Tan Gao wrote:
> urr, where's the string-to-array conversion?

Removed.

http://codereview.chromium.org/3323019/diff/1/2#newcode29
chromite/lib/cros_build_lib.py:29: cwd must point to the scripts directory.
On 2010/09/09 17:19:26, Tan Gao wrote:
> please add docstring for "shell" here

Done.

http://codereview.chromium.org/3323019/diff/1/2#newcode43
chromite/lib/cros_build_lib.py:43: if shell:
On 2010/09/09 17:20:16, sosa wrote:
> Since you are using shell to determine whether or not to interpret the cmd as
a
> string, why not just actually check to see if it is a string i.e. instanceof

Done.

http://codereview.chromium.org/3323019/diff/1/2#newcode47
chromite/lib/cros_build_lib.py:47: if enter_chroot: cmd = './enter_chroot.sh --
' + cmd
On 2010/09/09 17:19:26, Tan Gao wrote:
> "cmd" here is a string and in case of shell=True, it's a list?? i'm confused
> >__<

That's wrong. Fixed along with sosa's comment.

[Tan Gao, 2010-09-09 17:37:18]

LGTM!

[sosa, 2010-09-09 17:45:21]

nit o/w/ lgtm

http://codereview.chromium.org/3323019/diff/6001/7001
File chromite/lib/cros_build_lib.py (right):

http://codereview.chromium.org/3323019/diff/6001/7001#newcode29
chromite/lib/cros_build_lib.py:29: shell -- If shell is True, the specified
command will be executed through the shell.
80 chars :p