Regex basics

A regular expression is a pattern consisting of literal characters, an exact match, and special characters that have a variety of different behaviors. For example, the dot character, ".", matches any single character and not a literal dot.The -match operator, which was introduced in Chapter 5, Operators can be used to test if a string matches a regular expression. The left hand side of the operator expects a string, the right a regular expression. For example:

'cat' -match '.*' # Match anything, returns true
'cat' -match '\d' # Match digits, returns false

The meaning of the string on the right in these examples is explored during this chapter.A few basic characters can go a long way. Several of the most widely used characters and operators introduced in this section are summarized in Table 9.1:

Character	Description	Example
Any, except: [\^$.|?*+()	Literal character	'a' -match 'a' # True'a&apos...