So you can use the Term::Spinner module. It can be easily done manually, too:

$|=1; #autoflush

sub spin {
my @spinners = qw{/ - \ |};
my $index = $_[0];
print $spinners[$index]."\033[1D"; # man console_codes, ECMA-48 CSI se
+quences, "CUB"
return $index == 3 ? 0 : $index++;
}

my $j=0;
for (something) {
 do_something;
 $j=&spin($j);
}
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