Unicode Demystified

Using Unicode with Regular Expressions

In addition to normal searching where you match a literal pattern to a document (with potentially varying degrees of looseness in what constitutes a “match”), text is often searched for text that matches a regular expression. A regular expression describes a category of related strings. Any string in that category is said to “match” the regular expression. For example, a regular expression such as

p[a-z]*g

might be used to specify a category consisting of all words that start with p and end with g. “Pig,” “pug,” “plug,” and “piling” would all match this regular expression. If you searched a string for this regular expression, the search would stop on any of those words (or any other word that began with ...