Overwriting a print statement with one that is shorter in length - perl

Question

I am trying to overwrite a print statement in a foreach loop to create somewhat of a progress bar.
What I am doing:
my $arraySize = #listOfIps;
local $| = 1;
my $counter = 0;
my $progressString;
print 'Progress: ';
foreach my $ip (#listOfIps) {
$counter++;
print "\b" x length($progressString) if defined $progressString;
$progressString = "\r$counter / $arraySize - Working on $ip";
print $progressString;
#does stuff here but thats irrelevant to the problem
}
The problem I am having is that when the foreach loop gets to an IP that is shorter than the previous one it has printed eg 10.0.0.1 it still displays the extra characters left over from the previous longer print statement.
The problem:
Progress: 3 / 10 - Working on 200.144.223.211
then overwriting this print statement with the next smaller ip address in the array gives:
Progress: 4 / 10 - Working on 10.0.0.1223.211
and so on... when actually it should print just :
Progress: 4 / 10 - Working on 10.0.0.1
so that it does not have any of the characters from the previous print left over.
There must be something really obvious I am overlooking here, as I can't see any reason why this would not be working.

Answer 1

Use printf with a format that pads the IP string with spaces:
printf "\r$counter / $arraySize - Working on %-15s", $ip;
Adapt the number 15 to the length of your longest IP. If you have a variable, you can use it in the format string like so (thanks amon for sharing):
printf ".... Working on %-*s", $length, $ip;
Though that is quite excessive, since you can control all variable length strings with the printf:
printf "\r%-*s / %-*s - Working on %-*s", 5, $counter, 5, $arraySize, 15, $ip;
The \b escape is apparently a non-destructive backspace, which does not delete, according to this answer. Which would mean that it does just about the same as \r in your case.