Regex basics

A few basic characters can go a long way. A number of the most widely used characters and operators are introduced in this section and summarized in the following table:

Description	Character	Example
Literal character	Any except: [\^$.|?*+()	'a' -match 'a'
Any single character (except carriage return, line feed, \r, and \n)	.	'a' -match '.'
The preceding character repeated zero or more times	*	'abc' -match 'a*' 'abc' -match '.*'
The preceding character repeated one or more times	+	'abc' -match 'a+' 'abc' -match '.+'
Escape a character's special meaning	\	'*' -match '\*' '\' -match '\\'
Optional character	?	'abc' -match 'ab?c' 'ac' -match 'ab?c'

Debugging regular expressions

Regular expressions can quickly become complicated and difficult to understand. Modifying a complex regular expression is not a particularly simple undertaking.

While PowerShell indicates if there is a syntax error in a regular expression, it cannot do more than that; for example, PowerShell announces that there is a syntax error in...