#!/usr/bin/perl 

use strict; 
use Config; 

# check architecture and die if not as expected 
$Config{nvtype} eq "double" && $Config{doublesize} == 8 
        && $Config{ivtype} eq "long" && $Config{longsize} == 8 
        or die "not compatibile perl"; 

my $a = "-000123.456000"; 

# format good or die 
$a =~ /\G([-+]?(?=[0-9]|\.[0-9])[0-9]*(\.[0-9]*)?)/gc or die "not a number"; 
my $n = $1; 

# max length is 15, because architecure is such... convert string to number
length $n <= 15 + 2 or die "number too long";
$n = 0 + $n; 

# check if number fits within 15 digits
abs $n > 99999999999999.9 and die "number out of range";

print "$a ---> $n is OK\n"; 





....

root@orion:~# perl /tmp/aaaa
-000123.456000 ---> -123.456 is OK