DB<1> $_='abc'; s/a(b)c/$1/; print $_
b
  DB<2> $_='abc'; s/a(b)c/$1/e; print $_
b

##</code><code>##

  DB<1> $_='abc'; s/a(b)c/$1/; print $_
b
  DB<3> $_='abc'; m/a(b)c/; $_ = "$1" ; print $_
b

##</code><code>##

  DB<2> $_='abc'; s/a(b)c/$1/e; print $_
b
  DB<4> $_='abc'; m/a(b)c/; $_= eval '$1'; print $_
b

##</code><code>##

  DB<5> $_='warn 666'; s/(.*)/$1/e; print $_
warn 666
  DB<6> $_='warn 666'; m/(.*)/; $_= eval '$1'; print $_
warn 666

##</code><code>##

 
  DB<7> $_='warn 666'; s/(.*)/$1/ee; print $_
666 at (eval 171) ....    # skipped error message
1      # $_ = return code from warn
 
  DB<8> $_='warn 666'; m/(.*)/; $_= eval eval '$1';  print $_
666 at (eval 175). ... # skipped error message
1      # $_ = return code from warn

##</code><code>##

  DB<134> $hash{b}=666;
 
  DB<135> $_='abc'; s/a(b)c/$hash{$1}/; print $_
666
  DB<136> $_='abc'; m/a(b)c/; print "$hash{$1}";
666