Handy Regex search strings

This post will be updated occasionally to include strings I've found to be useful in day to day work.  A great way to test these is to simply go to regexr.com, paste in the body of text/strings you want to match against, and verify with your own regex strings whether they match or not.

• Negative lookahead for syslog string alerting.  Used primarily on Solarwinds syslog viewer, this should be placed in the message type field to discriminate against anything that includes the string "PLATFORM" in a syslog message.  All other messages will apply as normal.
  
  ^(?!.*PLATFORM).*$

• IPv4 address matching

           [0-9]+(?:\.[0-9]+){3}