subprocess - please enhance the documentation

[Helmut Jarausch]

Hi,

I'd like to suggest to add a few lines to chapter 17.1.3.5 "Replacing os.popen" 
(Python Doc 2.5.2)

I have used the following code in the past

ARC='MyDumpFile'
tar_inp= os.popen('/bin/tar cjf '+ARC+' -T -','w')
....
tar_exit_code= tar_inp.close()
if  tar_exit_code != None and tar_exit_code % 256 :
   print "some error messages"

When replacing this - as suggested - by

TAR= Popen(('/bin/tar','cjf',ARC,'-T','-'),stdin=PIPE)
tar_inp= TAR.stdin
....
tar_inp.close() always returns None.

So I have replaced this by

tar_inp.close()
tar_exit_code= TAR.wait()

if  tar_exit_code != 0 :
   print "some error messages"


Perhaps a few lines telling about this would be helpful.

Thanks,
Helmut.

-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany