scripts/warn-outside-container: fix font representation

[literally-user]

• supersedes, closes scripts/warn-outside-container: fix escapes #4211

Fixed font display in /scripts/warn-outside-container by replacing echo with POSIX-compatible prinf so that display works on any POSIX-compatible systems.

Fixes #6838

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[thaJeztah]

Thanks! I recall we had a PR for this, but it had some issues (#4211), so we can go with your PR instead; however, it looks like shellcheck linting is failing; can you fix that? (please amend the commit, so that there's only one commit in the PR)

[literally-user]

Oh, i see! Yeah, i'll fix that asap

[thaJeztah]

Thanks! I just tried, and looks like there was an issue; I posted the correct variant (you can copy/paste it.

[thaJeztah]

Some printf's didn't have an argument, causing a failure;

make binary WARNING: you are not in a container.printf: usage: printf [-v var] format [arguments] ./scripts/build/binary

We should also preserve the newlines (which echo automatically added); this should probably be the right one;

						printf "\n"
						printf "\033[1mWARNING\033[0m: you are not in a container.\n"
						printf "\n"
						printf 'Use "\033[1mmake dev\033[0m" to start an interactive development container,\n'
						printf 'use "\033[1mmake -f docker.Makefile %s\033[0m" to execute this target\n' "$target"
						printf "in a container, or set \033[1mDISABLE_WARN_OUTSIDE_CONTAINER=1\033[0m to\n"
						printf "disable this warning.\n"
						printf "\n"
						printf "Press \033[1mCtrl+C\033[0m now to abort, or wait for the script to continue..\n"

[literally-user]

Fixed. Thanks for your patience!