filesystem          kbytes   used     avail    capacity  mounted on
/dev/dsk/c0b0t0d0s4 12209400 5496486  6712914  46%       /home

##</code><code>##

sub parse_capacity {
   my ($df_output) = @_;
   my $capacity;
   if ($df_output =~ m[(\d+)%\s+/home$]) {
      $capacity = $1;
   }
   else {
      $capacity = 'Match Error';
   }
   return $capacity;
}

##</code><code>##

($df_output =~ m[(\d+)%\s+/home$]) ? $capacity = $1 : $capacity = 'Match Error';