CODEWITHSUNDEEP
pythonsubprocess
user3079257
user3079257

Reputation: 45

File gets created, but subprocess call says no such file or directory

I am trying to redirect the output of a subprocess call to a file

def get_arch():
    global ip_vm
    in_cmd = "uname -p"
    with open('/home/thejdeep/arch_list',"w") as outfile:
        print outfile
        subprocess.call(in_cmd,stdout=outfile)
        print "Hello"
    for i in ip_vm:
        cmd = "ssh thejdeep@"+i+" 'uname -p'"
        with open('/home/thejdeep/arch_list',"a") as outpfile:
                subprocess.call(cmd,stdout=outpfile)

The file gets created. This I get to know by printing outfile. However, the subprocess call returns a Errno[2] no such file or directory

Upvotes: 1

Views: 5008

Answers (1)

larsks
larsks

Reputation: 311703

Your first parameter to subprocess.call is incorrect. It should be a list, not a string. Compare:

>>> subprocess.call('echo hello')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python2.7/subprocess.py", line 522, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib64/python2.7/subprocess.py", line 710, in __init__
    errread, errwrite)
  File "/usr/lib64/python2.7/subprocess.py", line 1327, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

With:

>>> subprocess.call(['echo', 'hello'])
hello
0

If you really want to pass a shell command to subprocess.call, you need to set shell=True:

>>> subprocess.call('echo hello', shell=True)
hello
0

You are in general better off using the list version, because this way you don't need to worry about unexpected effects from shell metacharacters in your command strings.

Upvotes: 2

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