os.system and subprocess odd behavior

Dieter Maurer dieter at handshake.de
Sat Dec 15 08:12:15 CET 2012

py_genetic <conor.robinson at gmail.com> writes:

> Example of the issue for arguments sake:
> Platform Ubuntu server 12.04LTS, python 2.7
> Say file1.txt has "hello world" in it.
Here, you speak of "file1.txt" (note the extension ".txt")

> subprocess.Popen("cat < file1 > file2", shell = True)
> subprocess.call("cat < file1 > file2", shell = True)
> os.system("cat < file1 > file2")

But in your code, you use "file1" (without extension).

If your code really references a non-existing file, you may well
get what you are observing.

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