use strict;
use warnings;
use feature qw/say/;

my $string = "ph1-3;25;t3;t47-t50;d4-6";


my @output = map {
        s/^([[:alpha:]]+)(\d+)-(\d+)/$1$2-$1$3/;
        my ( $low, $high ) = split /-/;
        $low .. $high || $low;
} split /;/, $string;

say "@output";