To get the exact output, use Number :: FormatEng and Number :: Format :
use strict;
use warnings;
use Number::FormatEng qw(:all);
use Number::Format qw(:subs);
my $string = "54.4M" ;
my $string2 = "3.2G" ;
print format_number(unformat_pref($string)) , "\n";
print format_number(unformat_pref($string2)) , "\n";
__END__
54,400,000
3,200,000,000
By the way, it unformat_prefis only required if you are going to perform calculations with the result.
Number:: FormatEng ( ), . , k.
Number:: Format ( , ).
use Number::Format qw(:subs);
my $string = "54.4M" ;
my $string2 = "3.2G" ;
print round(unformat_number($string) , 0), "\n";
print round(unformat_number($string2), 0), "\n";
__END__
57042534
3435973837
, "", , Number::Format 1K 1024 , 1000 . , ( ), .