SC2094 triggers for: cat <<< "$(get_new_content f)" > f

[mminot-yseop]

As far as I know, this does not use the same pipeline and works perfectly reliably.

For bugs

• Rule Id (if any, e.g. SC1000): SC2094
• My shellcheck version (shellcheck --version or "online"): Bundled plugin in IntelliJ IDEA 2022.1.3.
• The rule's wiki page does not already cover this (e.g. https://shellcheck.net/wiki/SC2086)
• I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit

Here's a snippet or screenshot that shows the problem:

#! /usr/bin/env bash

get_new_content() {
    sed 's/Initial/Final/g' "${1:?}"
}

echo 'Initial content.' > f
cat f

# SHELLCHECK RULE TRIGGERED HERE:
cat <<< "$(get_new_content f)" > f

cat f

Output:

Initial content.
Final content.

(Also see, if you will, that SO answer I just created regarding that trick: https://stackoverflow.com/a/73054135/9089759)

Here's what shellcheck currently says:

Make sure not to read and write the same file in the same pipeline.

Here's what I wanted or expected to see:

Nothing.

[mminot-yseop]

(Loosely related to #473, perhaps, but it seemed different enough and I did not want to flood on someone else’s ticket.)