What good is G in a regular expression?
You use the \G anchor to start the next match on the same string where the last match left off. The regular expression engine cannot skip over any characters to find the next match with this anchor, so \G is similar to the beginning of string anchor, ^. The \G anchor is typically used with the g flag. It uses the value of pos() as the position to start the next match. As the match operator makes successive matches, it updates pos() with the position of the next character past the last match (or the first character of the next match, depending on how you like to look at it). Each string has its own pos() value. Suppose you want to match all of consecutive pairs of digits in a string like “1122a44” and stop matching when you encounter non-digits. You want to match 11 and 22 but the letter shows up between 22 and 44 and you want to stop at a. Simply matching pairs of digits skips over the a and still matches 44.
