I figure that your thinking is too complicated, especially when it comes to regex and processing the input lines.
Consider this code:

#!/usr/bin/perl
use strict;
use warnings;

while (my $line = <DATA>)
{
   next if $line =~ /^\s*$/; # skip blank lines
   $line =~ s/^\s*//;  # remove leading spaces
   $line =~ s/\s*$//;  # remove trailing space and line ending        
+                     

   my ($name, @nums) = split /[\s-]+/, $line;
   
   foreach my $num (@nums)
   {
      print "$name\t$num\n";
   }

}

# PRINTS
#abcd    723
#abcd    724
#abcde   552
#abcde   554
#abcde   553
#abcdef  756


__DATA__
abcd    723-724
abcde   552-554-553
abcdef  756
[download]

I don't think the trim leading and trailing spaces statements are needed here given your DATA. However, you should become familiar with how to do that.

Update: As a general rule:

• Use Regex when you know what to keep.
• Use Split when you know what to throw away.

This code works the same:

#!/usr/bin/perl
use strict;
use warnings;

while (my $line = <DATA>)
{
   next if $line =~ /^\s*$/; # skip blank lines
       
   my ($name, @nums) = $line =~ /(\w+)/g;
   
   foreach my $num (@nums)
   {
      print "$name\t$num\n";
   }

}

# PRINTS
#abcd    723
#abcd    724
#abcde   552
#abcde   554
#abcde   553
#abcdef  756


__DATA__
abcd    723-724
abcde   552-554-553
abcdef  756
[download]

I almost always have a statement to throw away blank lines. They can often appear at the end of a file and hard to see when you just type or cat the file.

---

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