updated for version 7.4.499 Problem: substitute() can be slow with long strings. Solution: Store a pointer to the end, instead of calling strlen() every time. (Ozaki Kiichi)

1 a aa abb abbcc
2 d dd dee deeff
3 g gg ghh ghhii
4 j jj jkk jkkll
5 m mm mnn mnnoo
6 x aa$ x
7 (a)(b) abba
8 axx ab]xx
9 foobar
9 foo