I wanted to use a python equivalent to piping some shell commands in perl. Something like the python version of open(PIPE, "command |").

I go to the subprocess module and try this:

p = subprocess.Popen("zgrep thingiwant largefile", shell=True, stdout=subprocess.PIPE)

This works for reading the output the same way I would in perl, but it doesn't clean itself up. When I exit the interpreter, I get

grep: writing output: Broken pipe

spewed all over stderr a few million times. I guess I had naively hoped all this would be taken care of for me, but that's not true. Calling terminate or kill on p doesn't seem to help. Look at the process table, I see that this kills the /bin/sh process, but leaves the child gzip in place to complain about the broken pipe.

What's the right way to do this?