Help for this page

Select Code to Download

Select or download this

 echo "Student Id Class
John 23 2
...
Sam 55 2
Tom 65 3
" | perl -ane '$F[2]=~/^\d+$/ or next;push @{$h[$F[2]]},$F[0]}{ $h[$_]
+ && print qq|Class $_ = |,join(",",@{$h[$_]}),qq|\n| for 0..$#h'

Select or download this

Class 2 = John,Jerry,Sam
Class 3 = Mark,Tom