How can I get stderr from os.popen()?

Question

If I call

os.popen('foo').read()

I want to capture

sh: foo: not found

as well.
I don't have the subprocess module since this is a minimal install on an embedded system.

popen3,4 doesn't work either:

 File "/usr/lib/python2.7/os.py", line 667, in popen3
import subprocess
ImportError: No module named subprocess

I suppose I could do

os.popen(command + " 2>&1").read()

to pipe it to stdout, but ideally I'd want to get it separately.

Answer 1

Since subprocess should be use in place of os.popen, you can do something like that

test.py:

from subprocess import PIPE, Popen

p = Popen("foo", shell=True, stdout=PIPE, stderr=PIPE)
stdout, stderr = p.communicate()
print "stdout: '%s'" % stdout
print "stderr: '%s'" % stderr

Now execute:

python test.py 
stdout: ''
stderr: '/bin/sh: 1: foo: not found
'

Notice the CR in stderr.