CODEWITHSUNDEEP
pythonbashif-statement
chanwcom
chanwcom

Reputation: 4680

How to check the result of the bash test command inside a python script?

I would like to run the bash "test" command inside a python script.

For example, in the bash sell script, this can be done easily as follows. #!/bin/bash

if ! test -s ${file}; then
  echo "${file} does not have a positive size. "
  # Do some processing.. 
fi

With a python script, I think I may try the following way:

#!/usr/bin/python
import subrocess

try:
  subprocess.check_call("test -s " + file, shell=True)
except:
  print file + " does not have a positive size. "
  # Do some process

Is the above approach a good way? If not, then could you please suggest an appropriate way?

Upvotes: 0

Views: 526

Answers (1)

Chris
Chris

Reputation: 1623

You shouldn't use shell=True unless it's necessary. Here, you can use subprocess.check_call(["test","-s",file]) without the security downsides of shell=True.

Aside from that, you can use built-ins to python rather than making subprocess calls. For instance, os has what you want here:

import os
try:
    if os.stat(file).st_size == 0:
        print "File empty." 
except OSError:
    print "File could not be opened."

Upvotes: 2

Related Questions