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

print "loops until 4 floats are entered\n";
for (1..4)
{
   my $float = get_float();
   print "$float Ok!!\n"
}   


sub get_float
{
   my $float;
   while ( (print"enter a float \(decimal required\): "), 
            $float = <STDIN>, 
            $float !~ /^\s*(\-|\+)?\d+\.\d*\s*$/)
   {
      print "Input not an float...try again\n";
   }
   $float =~ s/^\s*|\s*$//g; #delete leading/trailing spaces
   return $float;
}

__END__
perl getfloat.pl
loops until 4 floats are entered
enter a float (decimal required):   4.5.3
Input not an float...try again
enter a float (decimal required):         +4,5
Input not an float...try again
enter a float (decimal required):         +4.5
+4.5 Ok!!
enter a float (decimal required):   3
Input not an float...try again
enter a float (decimal required):   3.0
3.0 Ok!!
enter a float (decimal required):   -2.56
-2.56 Ok!!
enter a float (decimal required): +3
Input not an float...try again
enter a float (decimal required): 3.12345
3.12345 Ok!!