How about 
use strict;
use warnings;

my @nums =(
    '123-456-789',
    '123.789.456',
    '963 456 741',
    '123-456.789',
    '123 789-456',
    '963.456 741',
    '123456789',
    '123-456'
);

for my $num (@nums) {
    print "$num ";
    $num =~ s/[0-9]//g;
    if ($num =~ m/^([-. ])\1*$|^$/) {
        print "matches \n";
    } else {
        print "does not match \n";
    }
}

[download]
If the last number should not match, just delete the * in the regex

In reply to Re^3: Regex Modification by si_lence
in thread Regex Modification by Anonymous Monk

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