Negate match for word in the beginning of string i

Question

Let's say that I have following strings:

• mail to
• tel:[phone]
• http://www.google.fi
• mailto:[e-mail]
• hello world
• telephone
• elephant
• penny
• link
• owl

How can I find only strings that do not start with 'tel:', 'http://' and 'mailto:' in RE2 syntax?

I've tried following with following syntax, but it filters out all of them:

[^(https?://|tel:|mailto:)]

edit: RE2 syntax does not support negative lookbehind/lookahead.

Answer 1

There is no drop-in workaround for the lack of negative lookbehind on RE2 that I know of.

Why don't you match on strings that do start with those keywords instead? Then you can dismiss those.