my @matches = grep { $file[$_] =~ /^\Q$storeline|\E/ } 0..$#file;

[download]
Loops through an array "file" pulling out array indexes which start with the string "$storeline|" (whatever storeline is) and set @matches to the result. This could be written as, 
@matches = grep { /^\Q$storeline|\E/ } @file;

[download]
Calls the subroutine no_match passing $storeline as the arguement. returns if @matches is empty. 
no_match($storeline), return unless @matches;

[download]
Calls the subroutine duped_ids passing $storeline as the arguement. returns if the number of elements in @matches is greater than 1. 
duped_ids($storeline), return if @matches > 1;

[download]
</CODE>

In reply to Re: What does this mean by Sifmole
in thread Code explanation needed (was: What does this mean) by Anonymous Monk

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