Chapter 2. Regular Expression Reference

Regular expressions play an important role in most text parsing and text matching tasks. They form an important underpinning of the -split and -match operators, the switch statement, the Select-String cmdlet, and more. Tables 2-1 through 2-9 list commonly used regular expressions.

Table 2-1. Character classes: patterns that represent sets of characters

Character class

Matches

.

Any character except for a newline. If the regular expression uses the SingleLine option, it matches any character.

PS > "T" -match '.'
True

[characters]

Any character in the brackets. For example: [aeiou].

PS > "Test" -match '[Tes]'
True

[^characters]

Any character not in the brackets. For example: [^aeiou].

PS > "Test" -match '[^Tes]'
False

[start-end]

Any character between the characters start and end, inclusive. You may include multiple character ranges between the brackets. For example, [a-eh-j].

PS > "Test" -match '[e-t]'
True

[^start-end]

Any character not between any of the character ranges start through end, inclusive. You may include multiple character ranges between the brackets. For example, [^a-eh-j].

PS > "Test" -match '[^e-t]'
False

\p{character class}

Any character in the Unicode group or block range specified by {character class}.

PS > "+" -match '\p{Sm}'
True

\P{character class}

Any character not in the Unicode group or block range specified by {character class}.

PS > "+" -match '\P{Sm}'
False

\w

Any word character. Note that this is the Unicode definition ...

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