Print Byte Size in Human Readable Format

Description

humanReadable converts integer byte sizes to a human readable units such as kB, MB, GB, etc.

Usage

1
2
humanReadable(x, units="auto", standard=c("IEC", "SI", "Unix"),
              digits=1, width=NULL, sep=" ", justify=c("right", "left") )

Arguments

x

integer, byte size

standard

character, "IEC" for powers of 1024 ('MiB'), "SI" for powers of 1000 ('MB'), or "Unix" for powers of 1024 ('M'). See details.

units

character, unit to use for all values (optional), one of "auto", "bytes", or an appropriate unit corresponding to standard.

digits

integer, number of digits after decimal point

width

integer, width of number string

sep

character, separator between number and unit

justify

two-element vector specifiy the alignment for the number and unit components of the size. Each element should be one of "none", "left", "right", or "center"

Details

The basic unit used to store information in computers is a bit. Bits are represented as zeroes and ones - binary number system. Although, the binary number system is not the same as the decimal number system, decimal prefixes for binary multiples such as kilo and mega are often used. In the decimal system kilo represent 1000, which is close to 1024 = 2^{10} in the binary system. This sometimes causes problems as it is not clear which powers (2 or 10) are used in a notation like 1 kB. To overcome this problem International Electrotechnical Commission (IEC) has provided the following solution to this problem:

Name System Symbol Size Conversion
byte binary B 2^3 8 bits
kilobyte decimal kB 10^3 1000 bytes
kibibyte binary KiB 2^{10} 1024 bytes
megabyte decimal MB (10^3)^2 1000 kilobytes
mebibyte binary MiB (2^{10})^2 1024 kibibytes
gigabyte decimal GB (10^3)^3 1000 megabytes
gibibyte binary GiB (2^{10})^3 1024 mebibytes
terabyte decimal TB (10^3)^4 1000 gigabytes
tebibyte binary TiB (2^{10})^4 1024 gibibytes
petabyte decimal PB (10^3)^5 1000 terabytes
pebibyte binary PiB (2^{10})^5 1024 tebibytes
exabyte decimal EB (10^3)^6 1000 petabytes
exbibyte binary EiB (2^{10})^6 1024 pebibytes
zettabyte decimal ZB (10^3)^7 1000 exabytes
zebibyte binary ZiB (2^{10})^7 1024 exbibytes
yottabyte decimal YB (10^3)^8 1000 zettabytes
yebibyte binary YiB (2^{10})^8 1024 zebibytes

where Zi and Yi are GNU extensions to IEC. To get the output in the decimal system (powers of 1000) use standard="SI". To obtain IEC standard (powers of 1024) use standard="IEC".

In addition, single-character units are provided that follow (and extend) the Unix pattern (use standard="Unix"):

Name System Symbol Size Conversion
byte binary B 2^3 8 bits
kibibyte binary K 2^{10} 1024 bytes
mebibyte binary M (2^{10})^2 1024 kibibytes
gibibyte binary G (2^{10})^3 1024 mebibytes
tebibyte binary T (2^{10})^4 1024 gibibytes
pebibyte binary P (2^{10})^5 1024 tebibytes
exbibyte binary E (2^{10})^6 1024 pebibytes
zebibyte binary Z (2^{10})^7 1024 exbibytes
yottabyte binary Y (2^{10})^8 1024 zebibytes

For printout both digits and width can be specified. If width is NULL, all values have given number of digits. If width is not NULL, output is rounded to a given width and formated similar to human readable format of the Unix ls, df or du shell commands.

Value

Byte size in human readable format as character with proper unit symbols added at the end of the string.

Author(s)

Ales Korosec, Gregor Gorjanc, and Gregory R. Warnes greg@warnes.net

References

Wikipedia: http://en.wikipedia.org/wiki/Byte http://en.wikipedia.org/wiki/SI_prefix http://en.wikipedia.org/wiki/Binary_prefix

GNU manual for coreutils: http://www.gnu.org/software/coreutils/manual/html_node/Block-size.html#Block-size

See Also

object.size in package 'gdata', object.size in package 'utils', ll

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
# Simple example: maximum addressible size of 32 bit pointer
humanReadable(2^32-1)
humanReadable(2^32-1, standard="IEC")
humanReadable(2^32-1, standard="SI")
humanReadable(2^32-1, standard="Unix")

humanReadable(2^32-1, unit="MiB")
humanReadable(2^32-1, standard="IEC",  unit="MiB")
humanReadable(2^32-1, standard="SI",   unit="MB")
humanReadable(2^32-1, standard="Unix", unit="M")

# Vector of sizes
matrix(humanReadable(c(60810, 124141, 124, 13412513), width=4))
matrix(humanReadable(c(60810, 124141, 124, 13412513), width=4, unit="KiB"))

# Specify digits rather than width
matrix(humanReadable(c(60810, 124141, 124, 13412513), width=NULL, digits=2))

# Change the justification
matrix(humanReadable(c(60810, 124141, 124, 13412513), width=NULL,
                    justify=c("right", "right") ))

Want to suggest features or report bugs for rdrr.io? Use the GitHub issue tracker.