Python read windows Command Line output

Question

I am trying to execute a command in python and read its output on command line in windows.

I have written the following code so far:

def build():
 command = "cobuild archive"
 print "Executing build"
 pipe = Popen(command,stdout=PIPE,stderr=PIPE)
 while True: 
 line = pipe.stdout.readline()
 if line:
 print line

I want to execute the command cobuild archive in command line and read it's output. However, the above code is giving me this error.

 File "E:\scripts\utils\build.py", line 33, in build
 pipe = Popen(command,stdout=PIPE,stderr=PIPE)
 File "C:\Python27\lib\subprocess.py", line 679, in __init__
 errread, errwrite)
 File "C:\Python27\lib\subprocess.py", line 893, in _execute_child
 startupinfo)
WindowsError: [Error 2] The system cannot find the file specified

• mmmmmm: You need to indent your code
• JadedTuna: What happens when you enter that command in the shell?

Answer 1

The following code worked. I needed to pass shell=True for the arguments

def build(): 
command = "cobuild archive" 
pipe = Popen(command,shell=True,stdout=PIPE,stderr=PIPE) 
while True: 
 line = pipe.stdout.readline()
 if line: 
 print line
 if not line:
 break

Answer 2

WindowsError: [Error 2] The system cannot find the file specified

This error says that the subprocess module is unable to locate your executable(.exe)

here "cobuild archive"

Suppose, if your executable in this path: "C:\Users\..\Desktop", then, do,

import os
os.chdir(r"C:\Users\..\Desktop")

and then use your subprocess

• user3010197: Using output = commands.getstatusoutput(cmd) is giving me (1, "'{' is not recognized as an internal or external command,\noperable program or batch file.")
• user3010197: Also the batch file cobuild archive isn't triggered.
• Siva Cn: is your cobuild archive is an executable ?, to check this try running same from the command prompt (in the same directory), if its still throwing error, the problem is with your executable !!!
• user3010197: Yes. If I just run cobuild archive from the command prompt, it runs fine. I have been using that command from command line for a long time now. The executable isn't the problem. Its my python code.
• Siva Cn: Then in your subprocess call try, cmd = ["cobuild", "archive"], and pass this cmd to your subprocess

Answer 3

Do you mind to post your code with the correct indentations please? They have a large effect in python - another way of doing this is:

import commands
# the command to execute
cmd = "cobuild archive"
# execute and get stdout
output = commands.getstatusoutput( cmd )
# do something with output
# ...

Update:

The commands module has been removed in Python 3, so this is a solution for python 2 only.

https://docs.python.org/2/library/commands.html

• Siva Cn: The problem is not with the console read, but the execution itself
• Uli Köhler: Please post comments like "Do you mind to post your code with the correct indentations please?" as a comment, or just edit the original post - thanks!