问题
I need to implement an SVN pre-commit hook which executes a script that itself is stored in SVN.
I can use the svn cat command to pipe that script to the Python interpreter, as follows:
svn cat file://$REPO/trunk/my_script.py | python - --argument1 --argument2
However, my_script.py itself requires data to be piped on STDIN.
That data is not stored in a file; it is stored on the network. I would prefer not to have to download the data to a temporary file, as normally I could pipe it to a Python program:
curl http://example.com/huge_file.txt | python my_script.py
I'm not sure how to combine both of these pipes.
回答1:
I figured out how to do this without creating any temporary files, but not strictly with "pipes".
curl http://example.com/huge_file.txt | python <(svn cat file://$REPO/trunk/my_script.py) --argument1 --argument2
I used the "anonymous file descriptor" construct in Bash, which can be used in place of any file path.
E.g.
python my_script.py
would be equivalent to
python <(cat my_script.py)
回答2:
I don't think this is possible. You feed the script as standard input to the python interpreter. This means that the python interpreter is already attached to an input stream. I don't think the script contents can create a second standard input to read from.
来源：https://stackoverflow.com/questions/12397469/pipe-stdin-to-a-script-that-is-itself-being-piped-to-the-python-interpreter