python - Passing variables to a subprocess call

43
votes

I am trying to pass my variables from raw_input to my subprocess command. I am new to Python. Any help would he appreciated. 

#!/usr/bin/python

import subprocess

print "\nWhat user name"
username = str(raw_input('username: '))
print "\nWhat is the user id"
userid = int(raw_input('Enter user id: '))
print "\nWhat is the user\'s primary group?"
primarygroup = int(raw_input('Enter group: '))
print "\nWhat is the user\'s secondary group?"
secondarygroup = int(raw_input('Enter group: '))

subprocess.call(['useradd' '-m' '-g' _primarygroup '-G' _secondarygroup '-u' _userid _username])

print"\nThe user has been added"
6
pythonsubprocess
What problem are you having? Please be specific. - S.Lott
The "be specific" is -- hopefully -- a way for n00bz to think a little more clearly about their problem. - S.Lott
Really old but I'll note that, for example, the primary group was read into primarygroup but then attempted to be accessed via _primarygroup. - altendky

6 Answers

33
votes

Try separating the values with commas:

subprocess.call(['useradd', '-m', '-g', _primarygroup, '-G', _secondarygroup, '-u', _userid, _username])

See http://docs.python.org/library/subprocess.html#subprocess.call - It takes an array where the first argument is the program and all other arguments are passed as arguments to the program.

Also don't forget to check the return value of the function for a zero return code which means "success" unless it doesn't matter for your script if the user was added successfully or not.

7
votes

Try to add commas between your list items:

subprocess.call(['useradd', '-m', '-g', _primarygroup, '-G', _secondarygroup, \
                 '-u' ,_userid, _username])

subprocess.call takes the same arguments as subprocess.Popen:

args should be a string, or a sequence of program arguments.

Edit

To turn all your arguments into strings at once you could you a list comprehension:

args = ['useradd', '-m', '-g', _primarygroup, '-G', _secondarygroup, \
        '-u' ,_userid, _username]
str_args = [ str(x) for x in args ]
2
votes

You can create the arg string first and then just past this variable to the subprocess.call. For example:

projects_csv_fn = 'projects_csv_2.csv'
prjects_json_fn = 'projects.json'

args ='python json_to_csv.py id ' + prjects_json_fn + ' ' + projects_csv_fn

subprocess.call(args, shell=True)
0
votes
subprocess.call(['useradd', '-m','-g', _primarygroup, '-G', _secondarygroup, '-u', _userid, _username])

Pass a list to subprocess.call

0
votes

have you tried just using 'xxx{0}'.format(variable) ? see link1 or link2

subprocess.run(['useradd', '-m', '-g {0}'.format(_primarygroup), '-G {0}'.format(_secondarygroup), '-u {0}'.format(_userid)], capture_output=True)

or

subprocess.call(['useradd', '-m', '-g {0}'.format(_primarygroup), '-G {0}'.format(_secondarygroup), '-u {0}'.format(_userid)])

just worked fine to me

0
votes

You can also use f-strings.

 import subprocess

 site = 'google.com'
 subprocess.run(['nslookup', f'{site}'])