... @result = @fields[1,0,-1]; how does it work?

Please see Slices in perldata.

what is the '-1' in the end?

It's an array index. (Update: See Subscripts in perldata.) In Perl, negative indices access array elements from the end of the array:

c:\@Work\Perl\monks>perl -wMstrict -le
"my @ra = qw(first second some other stuff penultimate ultimate);
 ;;
 printf qq{$_ } for @ra[ 1, 0, -2, -1 ];
"
second first penultimate ultimate
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