$ perl -Mre=debug -e " $_=q{shabba}; $_ =~ q{shabba}
Compiling REx "shabba"
Final program:
   1: EXACT <shabba> (4)
   4: END (0)
anchored "shabba" at 0 (checking anchored isall) minlen 6
Guessing start of match in sv for REx "shabba" against "shabba"
Found anchored substr "shabba" at offset 0...
Guessed: match at offset 0
Freeing REx: "shabba"