positive regex for inverted match

[kgimpel]

I am passing a positive regex as a string argument to another function, and I'd only like to match on lines that don't contain "bar."

IE:

INPUT looks like this:
foo
"bar" blah
"test" blah
"test2"

MATCHES should be:
foo
"test" blah
"test2"

So, I effectively want to do this
$_ !~ /bar/
but I cannot change the logic to do it.

I've tried
/.*?(?!bat)/
but I think the line taken as a whole,
^.*bar.*$
satifies n-characters not followed by "bar," so we get a positive match. Can anyone suggest pattern for this?

Thanks in advance.