unitsコマンドは単位から単位の簡易計算に使えるツールです
A4用紙のサイズといった規格から、mからマイルへという変換も簡単にできます
実際のところ
例として3ミリ光秒*1とマイルの対応なんていう
(すくなくとも私は)突然新橋の路上で聞かれても回答できそうもない話も
# units "3 millilightseconds" miles
* 558.84719
/ 0.0017893979よく使う規格も定義されてますのでA4のサイズが見たいときには
# units "A4paper"
Definition: 210 mm 297 mm = 0.06237 m^2さらに中々凄まじい事に、日本ローカルな坪や尺貫法、古代ローマの単位なんてのまで定義されています。
# units "4.5 edoma" m2
* 6.9504132
/ 0.14387634
# units "4.5 jou_area" m2
* 6.9504132
/ 0.14387634約25枚のA4紙は約1畳(江戸間)！
# units "1 edoma" A4paper
* 24.76409
/ 0.040381052
何故か指輪のサイズまでわかる
日本規格の指輪の内径サイズまで分かります……ナンデ？？？
# units "jpringsize(10)" cm
* 5.0265482
/ 0.19894368定義をみると……結構複雑なことをやっている
# Japanese sizes start with size 1 at a 13mm inside diameter and each size is
# 1|3 mm larger in diameter than the previous one. They are multiplied by pi
# to give circumference.
jpringsize(n) units=[1;mm] domain=[1,) range=[0.040840704,) \
(38|3 + n/3) pi mm ; 3 jpringsize/ pi mm + (-38)
蛇足
あまりに面白すぎたので日本部分の定義ファイルを転載
#
# Traditional Japanese units (shakkanhou)
#
# The traditional system of weights and measures is called shakkanhou from the
# shaku and the ken. Japan accepted SI units in 1891 and legalized conversions
# to the traditional system. In 1909 the inch-pound system was also legalized,
# so Japan had three legally approved systems. A change to the metric system
# started in 1921 but there was a lot of resistance. The Measurement Law of
# October 1999 prohibits sales in anything but SI units. However, the old
# units still live on in construction and as the basis for paper sizes of books
# and tools used for handicrafts.
#
# Note that units below use the Hepburn romanization system. Some other
# systems would render "mou", "jou", and "chou" as "mo", "jo" and "cho".
#
#
# http://hiramatu-hifuka.com/onyak/onyindx.html
# Japanese Proportions. These are still in everyday use. They also
# get used as units to represent the proportion of the standard unit.
wari_proportion 1|10
wari wari_proportion
bu_proportion 1|100 # The character bu can also be read fun or bun
# but usually "bu" is used for units.
rin_proportion 1|1000
mou_proportion 1|10000
# Japanese Length Measures
#
# The length system is called kanejaku or
# square and originated in China. It was
# adopted as Japan's official measure in 701
# by the Taiho Code. This system is still in
# common use in architecture and clothing.
shaku 1|3.3 m
mou 1|10000 shaku
rin 1|1000 shaku
bu_distance 1|100 shaku
sun 1|10 shaku
jou_distance 10 shaku
jou jou_distance
kanejakusun sun # Alias to emphasize architectural name
kanejaku shaku
kanejakujou jou
# http://en.wikipedia.org/wiki/Taiwanese_units_of_measurement
taichi shaku # http://zh.wikipedia.org/wiki/台尺
taicun sun # http://zh.wikipedia.org/wiki/台制
!utf8
台尺 taichi # via Hanyu Pinyin romanizations
台寸 taicun
!endutf8
# In context of clothing, shaku is different from architecture
# http://www.scinet.co.jp/sci/sanwa/kakizaki-essay54.html
kujirajaku 10|8 shaku
kujirajakusun 1|10 kujirajaku
kujirajakubu 1|100 kujirajaku
kujirajakujou 10 kujirajaku
tan_distance 3 kujirajakujou
ken 6 shaku # Also sometimes 6.3, 6.5, or 6.6
# http://www.homarewood.co.jp/syakusun.htm
# mostly unused
chou_distance 60 ken
chou chou_distance
ri 36 chou
# Japanese Area Measures
# Tsubo is still used for land size, though the others are more
# recognized by their homonyms in the other measurements.
gou_area 1|10 tsubo
tsubo 36 shaku^2 # Size of two tatami = ken^2 ??
se 30 tsubo
tan_area 10 se
chou_area 10 tan_area
# http://en.wikipedia.org/wiki/Taiwanese_units_of_measurement
ping tsubo # http://zh.wikipedia.org/wiki/坪
jia 2934 ping # http://zh.wikipedia.org/wiki/甲_(单位)
fen 1|10 jia # http://zh.wikipedia.org/wiki/分
fen_area 1|10 jia # Protection against future collisions
!utf8
坪 ping # via Hanyu Pinyin romanizations
甲 jia
分 fen
分地 fen_area # Protection against future collisions
!endutf8
# Japanese architecture is based on a "standard" size of tatami mat.
# Room sizes today are given in number of tatami, and this number
# determines the spacing between colums and hence sizes of sliding
# doors and paper screens. However, every region has its own slightly
# different tatami size. Edoma, used in and around Tokyo and
# Hokkaido, is becoming a nationwide standard. Kyouma is used around
# Kyoto, Osaka and Kyuushu, and Chuukyouma is used around Nagoya.
# Note that the tatami all have the aspect ratio 2:1 so that the mats
# can tile the room with some of them turned 90 degrees.
#
# http://www.moon2.net/tatami/infotatami/structure.html
edoma (5.8*2.9) shaku^2
kyouma (6.3*3.15) shaku^2
chuukyouma (6*3) shaku^2
jou_area edoma
tatami jou_area
# Japanese Volume Measures
# The "shou" is still used for such things as alcohol and seasonings.
# Large quantities of paint are still purchased in terms of "to".
shaku_volume 1|10 gou_volume
gou_volume 1|10 shou
gou gou_volume
shou (4.9*4.9*2.7) sun^3 # The character shou which is
# the same as masu refers to a
# rectangular wooden cup used to
# measure liquids and cereal.
# Sake is sometimes served in a masu
# Note that it happens to be
# EXACTLY 7^4/11^3 liters.
to 10 shou
koku 10 to # No longer used; historically a measure of rice
# Japanese Weight Measures
#
# http://wyoming.hp.infoseek.co.jp/zatugaku/zamoney.html
# Not really used anymore.
rin_weight 1|10 bu_weight
bu_weight 1|10 monme
fun 1|10 monme
monme momme
kin 160 monme
kan 1000 monme
kwan kan # This was the old pronounciation of the unit.
# The old spelling persisted a few centuries
# longer and was not changed until around
# 1950.
参考もと
本の虫: 500マイル以上離れた場所にメールが送れないのだが
man units (1): unit conversion and calculation program
units(1): unit conversion program - Linux man page
*1:なんて単位がある事自体、今の今まで忘れていました
