/ 
Number-Bytes-Human-0.03
River stage two • 16 direct dependents • 17 total dependents
/ Number::Bytes::Human

NAME

Number::Bytes::Human - Convert byte count to human readable format

SYNOPSIS

use Number::Bytes::Human qw(format_bytes);
$size = format_bytes(0); # '0'
$size = format_bytes(2*1024); # '2.0K'

$size = format_bytes(1_234_890, bs => 1000); # '1.3M'
$size = format_bytes(1E9, bs => 1000); # '1.0G'

# the OO way
$human = new Number::Bytes::Human(bs => 1000, si => 1);
$size = $human->format(1E7); # '10MB'
$human->set_options(zero => '-');
$size = $human->format(0); # '-'

DESCRIPTION

THIS IS ALPHA SOFTWARE: THE DOCUMENTATION AND THE CODE WILL SUFFER CHANGES VERY SOON (THANKS, GOD!).

This module provides a formatter which turns byte counts to usual readable format, like '2.0K', '3.1G', '100B'.

byte      B
kilobyte  K = 2**10 B = 1024 B
megabyte  M = 2**20 B = 1024 * 1024 B
gigabyte  G = 2**30 B = 1024 * 1024 * 1024 B
terabyte  T = 2**40 B = 1024 * 1024 * 1024 * 1024 B

petabyte  P = 2**50 B = 1024 * 1024 * 1024 * 1024 * 1024 B
exabyte   E = 2**60 B = 1024 * 1024 * 1024 * 1024 * 1024 * 1024 B
zettabyte Z = 2**70 B = 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024 B
yottabyte Y = 2**80 B = 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024 * 1024 B

I have found this link to be quite useful:

http://www.t1shopper.com/tools/calculate/

If you feel like a hard-drive manufacturer, you can start counting bytes by powers of 1000 (instead of the generous 1024). Just use bs => 1000.

If you feel like a purist academic, you can force the use of metric prefixes according to the Dec 1998 standard by the IEC. Never mind the units for base 1000 are ( 'B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB' ) and, even worse, the ones for base 1024 are ( 'iB', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB' ) with the horrible names: bytes, kibibytes, mebibytes, etc. All you have to do is to use si => 1. Ain't that beautiful the SI system? Read about it:

http://physics.nist.gov/cuu/Units/binary.html

You can try a pure Perl "ls -lh"-inspired command with the one-liner, er, two-liner:

$ perl -MNumber::Bytes::Human=format_bytes \
       -e 'printf "%5s %s\n", format_bytes(-s), $_ for @ARGV' *

Why to write such a module? Because if people can write such things in C, it can be written much easier in Perl and then reused, refactored, abused. And then, when it is much improved, some brave soul can port it back to C (if only for the warm feeling of painful programming).

OPTIONS

BASE
block | base | block_size | bs => 1000 | 1024
base_1024 | block_1024 | 1024 => 1
base_1000 | block_1000 | 1000 => 1

The base to be used: 1024 (default) or 1000.

Any other value throws an exception.

ZERO
zero => string | undef

The string 0 maps to ('0' by default). If undef, the general case is used. The string may contain '%S' in which case the suffix for byte is used.

format_bytes(0, zero => '-') => '-'
METRIC SYSTEM
si => 1
ROUND
round_function => $coderef
round_style => 'ceil' | 'floor'
TO_S
QUIET
quiet => 1

Suppresses the warnings emitted. Currently, the only case is when the number is large than $base**(@suffixes+1).

OBJECTS

An alternative to the functional style of this module is the OO fashion. This is useful for avoiding the unnecessary parsing of the arguments over and over if you have to format lots of numbers

for (@sizes) {
  my $fmt_size = format_bytes($_, @args);
  ...
}

vs.

my $human = new Number::Format::Bytes(@args);
for (@sizes) {
  my $fmt_size = $human->format($_);
  ...
}

MAKE IT JUST A MATTER OF STYLE: memoize _parse_args() for $seed == undef

EXPORT

It is alright to import format_bytes, but nothing is exported by default.

DIAGNOSTICS

"unknown round style '$style'";

"invalid base: $block (should be 1024 or 1000)";

"round function ($args{round_function}) should be a code ref";

"suffixes ($args{suffixes}) should be an array ref";

"negative numbers are not allowed" (??)

SEE ALSO

lib/human.c and lib/human.h in GNU coreutils.

The _convert() solution by COG in Filesys::DiskUsage.

BUGS

Please report bugs via CPAN RT http://rt.cpan.org/NoAuth/Bugs.html?Dist=Number-Bytes-Human.

AUTHOR

Adriano R. Ferreira, <ferreira@cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2005 by Adriano R. Ferreira

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.