"I'm looking for an interesting discussion of ways and means" 

#!/usr/bin/perl

use strict; # https://www.perlmonks.org/?node_id=11154990
use warnings;
use feature 'bitwise';
use List::AllUtils qw( reduce );

my @floats = (
    [ '0.',                         'valid' ],
    [ '0.007',                      'valid' ],
    [ '.757',                       'valid' ],
    [ '125.89',                     'valid' ],
    [ '+10789.24',                  'valid' ],
    [ '+107894',                    'valid' ],
    [ '-0.0008',                    'valid' ],
    [ 'The temperature is 28.79C',  'valid' ],
    [ 'Frequency: 10877.45Hz',      'valid' ],
    [ '255.0.0.0',                'invalid' ],
    [ '255.aa',                     'valid' ],
    [ "10.13.2023, today's date", 'invalid' ],
    [ '0.119.255.255' ,           'invalid' ],
    [ 'Date: 10.13.2023 BC',      'invalid' ],
    [ '-42',                        'valid' ],
    [ '2004.04.12 Friedl nomatch','invalid, Friedl pg 195' ],
    [ 'all of 12.34 and 3.4.5.6 and 37' ],
    [ '300 10.16.2023 -42 255.0.0.0 lucky 7' ],
);
my $leftside = length reduce {$a |. $b->[0]} @floats; # auto-adjust

for my $str ( map $_->[0], @floats )
  {
  my @numbers = grep /./, $str =~ /(?|
    (?:(?:\d+\.){2,}\d+)()
    |
    ([+-]?(?:\d+(?:\.\d*)?|\.\d+))
    )/gx;
  printf "%*s   %s\n", $leftside, $str, "@numbers";
  }

[download]

Outputs: 

                                  0.   0.
                               0.007   0.007
                                .757   .757
                              125.89   125.89
                           +10789.24   +10789.24
                             +107894   +107894
                             -0.0008   -0.0008
           The temperature is 28.79C   28.79
               Frequency: 10877.45Hz   10877.45
                           255.0.0.0   
                              255.aa   255.
            10.13.2023, today's date   
                       0.119.255.255   
                 Date: 10.13.2023 BC   
                                 -42   -42
           2004.04.12 Friedl nomatch   
     all of 12.34 and 3.4.5.6 and 37   12.34 37
300 10.16.2023 -42 255.0.0.0 lucky 7   300 -42 7

[download]

In reply to Re: Best practice validating numerics with regex? by tybalt89
in thread Best practice validating numerics with regex? by perlboy_emeritus

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