Python subprocess with heredocs
heredoc, python, subprocess
Solution
The shell "heredoc" support is a shell feature. `subprocess.Popen` does not run your command through the shell by default, so this syntax certainly won't work.
However, since you're using pipes anyway, there isn't any need to use the heredoc support of the shell. Just write your string `a` to the stdin pipe of the process you just started. This is exactly what the shell would do with the heredoc anyway.
You can do this with `Popen.communicate()`:
p.communicate(a)
The return value of the `communicate()` function contains the output of the process (in two streams, see the docs).
Problem
I was playing around with Python's subprocess module, trying a few examples but I can't seem to get heredoc statements to work. Here is the trivial example I was playing with: ``` import subprocess a = "A String of Text" p = subprocess.Popen(["cat", "<<DATA\n" + a + "\nDATA"]) ``` I get the following error when I run the code above: ``` cat: <<DATA\nA String of Text\nDATA: No such file or directory ``` Am I doing it wrong? Is this even possible? If so how would I go about doing it? Update Just wanted to say that this should never be performed in a real python program because there are better ways of doing this.