A typical approach for accessing a compiled Pattern instance is to use Pattern p = Pattern.compile(""); with the relevant regular expression specified within the pair of double quotes.

The first time I ever encountered a regular expression was many years ago now, but I still remember my first thoughts on it: What is this string-like thing? I don’t want to touch it, it looks ...

However, regular expression functions are available in many programming languages that allow for complex pattern matching and text manipulation.

A regular expression, also known as a regex or regexp, is a string whose pattern (template) describes a set of strings. The pattern determines which strings belong to the set.

Javascript’s regular expression library is becoming world class, guaranteeing that the odd little pattern language will likely be around for generations to come.

To find the opposite I would probably use the -notmatch operator instead of futzing with the regular expression pattern. PS C:\> get-process | where {$_.company -notmatch "^Microsoft|Google"} | select ...

grep - the command for searching and printing lines matching a pattern. -E - Enables extended regular expression syntax. ' - First of two single quotes which surround the regular expression.

Even if you aren’t a regular expression guru, it is easy to use grep to search for lines in a file that match anything from simple strings to complex patterns.