python subprocess.Popen

Question

I am having a difficult time understanding how to get python to call a system command with the subprocess.Popen function.

the_file = ('logs/consolidated.log.gz')         
webstuff = subprocess.Popen(['/usr/bin/zgrep', '/meatsauce/', the_file ],stdout=subprocess.PIPE)
  for line in webstuff.stdout:
    print line

Trying to get python to build another file with my search string.

Answer 1

The problem is in how you're constructing your arguments. The way you have it now, you're running:

/usr/bin/zgrep /meatsauce/ logs/consolidated.log.gz

Note the space between /meatsauce/ and logs ...

To do what I think you're intending, use os.path.join a la:

import os

the_file = 'logs/consolidated.log.gz'         
webstuff = subprocess.Popen(['/usr/bin/zgrep', os.path.join('/meatsauce/', the_file)],stdout=subprocess.PIPE) % dpt_search
    for line in webstuff.stdout:
        print line

Answer 2

Not exactly sure about your question, but the following snippet will call zgrep with two arguments, a searchterm and a filename - and print the result ( stdout ) line by line:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import subprocess

# filename and searchterm
fn, term = 'access_log.gz', 'hello'
p = subprocess.Popen(['/usr/bin/zgrep', term, fn], stdout=subprocess.PIPE)
for line in p.stdout:
    print line

In the code you posted the string interpolation ( % dpt_search ) does not work out, since there is not pure string in front of the modulo sign - in fact it should fail with something like:

TypeError: "unsupported operand type(s) for %: 'Popen' and 'str'"

Answer 3

the_file = ('webalizerlogs/consolidated.log.gz')
output_f = open('output.txt','w')
webstuff = subprocess.Popen(['/usr/bin/zgrep', dpt_search, the_file ],stdout=output_f)

Answer 4

I think you are simply trying to grep the a content in the a file. Is it?

import os
import subprocess
the_file = os.path.join(os.getcwd(),'logs/consolidated.log.gz')
proc = subprocess.Popen(['/usr/bin/zgrep', dpt_search, the_file], stdout=subprocess.PIPE)
out, err = proc.communicate()
with open('resultoutput','w') as f:
     f.write(out)
subprocess.call(['/usr/bin/zip',os.path.join(os.getcwd(),'resultoutput'])

Check the docs as well.