Manual:Regular Expressions
RouterOS support POSIX regular expression syntax (POSIX standard), with some exceptions:
- '{}' bounds are not supported;
- "()" must not be empty;
- equivalence classes are not supported ("[[.ch.]]");
- collating elements are not supported ("[[=a=]b]");
- matching is done in single pass, no backtracking.
Following services in RouterOS are using Regexps:
- firewall L7 matchers
- BGP filters
- CAPSMAN provisioning
- TFTP
- Web Proxy
- Hotspot Walled Garden
- DNS
- Console with '~' operator