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I am trying to replace os.system calls with subprocess.Popen. This simple
example fails miserably:

>>> proc = subprocess.Popen ("ls /tmp")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/titan/skipm/local/lib/python2.5/subprocess.py", line 594, in __init__
errread, errwrite)
File "/home/titan/skipm/local/lib/python2.5/subprocess.py", line 1091, in
_execute_child
raise child_exception
OSError: [Errno 2] No such file or directory

I also tried explicitly referencing /usr/bin/ls. Same result. What gives?
I see this behavior in both Python 2.4 and 2.5 on Solaris 10 and with
2.6alpha on Mac OS X.

Frustrated in Chicago...

Skip

Skip Montanaro wrote:

> I am trying to replace os.system calls with subprocess.Popen. Â*This simple
> example fails miserably:
>
>>>> proc = subprocess.Popen ("ls /tmp")

Popen expects a list of program arguments. When passed a single string
instead of a list, as in your example, it assumes that the string is the
command, and looks for an executable named "ls /tmp", which of course does
not exist.

Split your command into a list of separate parameters, with the executable
as the first parameter, and it will work:

>>> subprocess.Popen(['ls', '/tmp'])
<subprocess.Popen object at 0xb7c569ec>
>>> (ls output here)


Jeffrey

On Mar 27, 10:53 am, Skip Montanaro <s...@pobox.com> wrote:

> Is subprocess.Popen completely broken?

Your lack of faith in Python is somewhat disturbing ...

"Istvan Albert" schrieb
>
> > Is subprocess.Popen completely broken?
>
> Your lack of faith in Python is somewhat
> disturbing ...
>
I have consistently made the experience that when
I was about to ask "is X completely broken", the
error was on my side.

Martin