Regular Expressions

REs match anywhere on a line
for example: ape, will match grape,ape,runescape, but not A.P.E.
by default, case-sensitive
searching for default: will require the colon to follow the word default
backslashes escape metacharacters
splunk, elasticsearch, logstash, C#, python, C++, awk, sed, perl, grep, vi all use REs