As already stated you must show some effort, even for basic questions.

The data part (peter, john..) it is very easy (profit links given by other monks, search also chomp and split between functions )

The headers by other hand, are formatted in a very bad way, that make the appropriate parsing difficult, at least to me. To rearrange headers you need to achieve a datastructure like the following:

[Student][]       [science][]      [total]
[]       [Roll_no][]       [Cutoff][student]
[Name]   []       [Mark]   []      [mark]
[download]

and then join all columns of the array of array, skipping undef values to have them correctly ordered.

Better if you can have headers formatted differently or even if you can hardcode them into the program.

The Perl Cookbook is aged but has tasty recipes about reading from files, if i recall correctly.

L*