shell quoting in templates, especially for command_line integration

[tianon]

Describe the enhancement

While using the command_line integration, I'm creating sensors using shell commands and it strikes me as odd that I can't find an "escape for shell" function/filter in either jinja2 upstream or the HA additions for safely passing arbitrary HA data to shell commands.

Example usage

Example:

echo {{ "foo\n'\nbar" | sh }}


would output:

echo 'foo
'"'"'
bar'

Current workarounds

Mostly hoping and praying (echo '{{ ... }}').

Anything else?

What I'm looking for is something similar to jq's @sh filter: https://jqlang.org/manual/v1.8/#format-strings-and-escaping:~:text=%2C%20%5C%5C%20respectively.-,%40sh,-%3A

Since Python 3.3, the stdlib shlex class includes a quote function that should do exactly what I'm think of: https://docs.python.org/3.14/library/shlex.html#shlex.quote (big important Windows / non-POSIX shell caveat there which would probably be good to mirror into HA docs)

[tianon]

would output:

echo 'foo
'"'"'
bar'

To be clear, I chose this representation for my example by passing this string through python3's shlex.quote function:

$ python3 -c 'import shlex; print(shlex.quote("foo\n'\''\nbar"))'
'foo
'"'"'
bar'

Just to illustrate, here's the same from jq:

$ jq -nr '"foo\n'\''\nbaz" | @sh'
'foo
'\''
baz'

So there are other ways this could be sliced/represented, but the problem space does have some subtleties that make it worthwhile (IMO) to use a pre-existing library/function for it, especially since there's one already in the Python stdlib. 😄 ❤️