oguz-ismail 1 day ago

Dunno, so much work to achieve so little. I'm even more inclined to stick with shell scripts now

2
kragen 1 day ago

The Bourne shell is definitely less work unless you want your code to correctly or reliably handle user input. Then it's more work.

oguz-ismail 1 day ago

Not in my experience. Any concrete examples off the top of your head, where it's more work than setting up pipes in python manually?

baobun 12 hours ago

Fill in the blank to run a docker container which opens the file with user-provided path in (say) vim.

docker run --rm -it ...?

Now run a container doing the exact same thing ("docker-in-docker").

docker run --rm -it -v $DOCKER_HOST:/var/run/docker.sock ...?

oguz-ismail 11 hours ago

> Fill in the blank to run a docker container which opens the file with user-provided path in (say) vim.

Never used docker before, but this seems to work:

    docker run --rm -it debian bash -c 'vim -- "$1"' _ "$user_provided_path"

kragen 59 minutes ago

Looks relatively safe to me, though it doesn't seem to work because debian:latest doesn't have vim in it (so I'm skeptical of your implicit claim of having tried it), and, if $user_provided_path is empty, it defaults to browsing the filesystem. But there are a lot of characters there that are specifically there to avoid footguns; without them, it would seem to work, but it would fail when $user_provided_path contained special characters.

The version I tested was

    docker run --rm -it debian bash -c 'apt update; apt install -y vim; vim -- "$1"' _ "$user_provided_path"

oguz-ismail 50 minutes ago

> your implicit claim of having tried it

I tried printing positional parameters, they looked fine. (And already uninstalled docker. What's the point of containerization if you need superuser privileges to use it?)

> if $user_provided_path is empty, it defaults to browsing the filesystem

That's what

    vim -- ""
does.

> But there are a lot of characters there that are specifically there to avoid footguns

What are those characters? --? That's not a lot

hollerith 23 hours ago

The Python code Kragen gave is more characters to type, but fewer footguns.

Shell scripts are much higher in footguns per character than most programming languages.

It is possible for a coder to understand bash so well that he never shoots his own foot off, but it requires more learning hours than the same feat in another language requires, and unless I've also put in the (many) learning hours, I have no way of knowing whether a shell script written by someone I don't know contains security vulnerabilities or fragility when dealing with unusual inputs that will surface in unpredictable circumstances.

The traditional Unix shell might be the most overrated tool on HN.

oguz-ismail 13 hours ago

> The Python code Kragen gave is more characters to type, but fewer footguns.

What are the footguns in this?

    df | grep /$

hollerith 4 hours ago

There are none AFAIK.

Allow me to correct my previous comment: using Python's os.spawnlp or Popen to invoke Unix commands has fewer footguns than using the shell. (Kragen's code only addresses your question of how to set up a pipeline in Python.)