GREP in InDesign

Repeat: Sequences of Characters

Without GREP, to replace sequences of space characters with just a single space, you had to repeatedly replace two spaces with one until there were no more double spaces left. GREP makes this much simpler; search any sequence of more than one space and replace with a single one: find \x{20}\x{20}+ and replace with \x{20}.

As we’ve seen earlier, the plus is a repeat character and means “at least once,” so that the expression paraphrases as “find a space followed by a sequence of at least one space.” There are several repeat characters; they’re all in the Repeat flyout (see Figure 7). We’ll deal with them in turn.

? Zero or One Time

To find, say, both British and American spellings harbour of harbor, search for harbou?r. The scope of ? is just one character, so in this example it applies only to the u. The expression paraphrases as “find harbo, perhaps followed by u (or, followed by zero or one occurrence of u), followed by r.” To extend the scope of ? to more characters, group them with parentheses: (19)?\d\d finds all two-digit numbers (matched by \d\d), as well as four-digit numbers whose first two digits are 19. You can combine this with alternation: (18|19|20)?\d\d matches two-digit numbers as well as four-digit numbers that begin with 18, 19, or 20.

The ? operator is useful for matching numbers as well—for example, in dates. The expression \d\d-\d\d-\d\d\d\d finds dates formatted like 08-04-2007. But dates come in different shapes, so to allow ...