Regular Expressions Cookbook

2.7. Unicode Code Points, Properties, Blocks, and Scripts

Problem

Use a regular expression to find the trademark sign (™) by specifying its Unicode code point rather than copying and pasting an actual trademark sign. If you like copy and paste, the trademark sign is just another literal character, even though you cannot type it directly on your keyboard. Literal characters are discussed in Recipe 2.1.

Create a regular expression that matches any character that has the “Currency Symbol” Unicode property. Unicode properties are also called Unicode categories.

Create a regular expression that matches any character in the “Greek Extended” Unicode block.

Create a regular expression that matches any character that, according to the Unicode standard, is part of the Greek script.

Create a regular expression that matches a grapheme, or what is commonly thought of as a character: a base character with all its combining marks.

Solution

Unicode code point

\u2122

Regex options: None

Regex flavors: .NET, Java, JavaScript, Python

This regex works in Python only when quoted as a Unicode string: u"\u2122".

\x{2122}

Regex options: None

Regex flavors: PCRE, Perl, Ruby 1.9

PCRE must be compiled with UTF-8 support; in PHP, turn on UTF-8 support with the /u pattern modifier. Ruby 1.8 does not support Unicode regular expressions.

Unicode property or category

\p{Sc}

Regex options: None

Regex flavors: .NET, Java, PCRE, Perl, Ruby 1.9

PCRE must be compiled with UTF-8 support; in PHP, turn on UTF-8 support with the /u pattern ...