w=write;p=paste;r=rep
w(a<-c("world","hello","world!"),"")
w(x<-p(r(a[2:3],e=3),a),"")
for(i in 1:3)if(i==3)w(p(r(x,e=3),a)[1:19],"")else w(x<-p(r(x,e=3),a),"")
Note that non-ascii characters in the above source code will be escaped (such as \x9f).