原文： http://i.linuxtoy.org/docs/guide/ch02s02.html

缩写习惯

构建于图表界面之上的操作系统，使用鼠标作为主输入设备，是否使用缩写并不重要。比如Windows系统中的目录，几乎都是全称。。。点击两次鼠标进入文件夹pf，并不意味着点击13次才能进入文件夹Program Files

而构建于命令行之上的操作系统，如Linux，只要3个字母以上的单词，几乎都要缩写。例如:cd命令是Change Directory的缩写。作为常用命令，如果使用它的全称Change Directory绝对是无聊和乏味的工作。

最常见的缩写，取每个单词的首字母，如

cd Change Directory
dd Disk Dump
df Disk Free
du Disk Usage
pwd Print Working Directory
ps Processes Status
PS Prompt Strings
su Substitute User
rc Run Command
Tcl Tool Command Language
cups Common Unix Printing System
apt Advanced Packageing Tool
bg BackGround
ping Packet InterNet Grouper

如果首字母后为h，通常保留

chsh CHange SHell
chmod CHange MODe
chown CHange OWNer
chgrp CHange GRoup
bash Bourne Again SHell
zsh Z SHell
ksh Korn SHell ssh Secure SHell

递归缩写也属于这一类，如：

GNU GNU’s Not Unix
PHP PHP: Hypertext Preprocessor
RPM RPM Package Manager
WINE WINE Is Not an Emulator
PNG PNG’s Not Gif
nano Nano’s ANOther editor

** 有些缩写可能有多种定义，如：

rpm

RPM Package Manager

RetHad Package Manager

bc

Basic Calculator

Better Calculator

这方面Emacs可谓独领风骚：

Emacs May Allow Customized Screwups
Emacs Manuals Are Cryptic and Surreal
Eventually Munches All Computer Storage
Eight Megabytes And Constantly Swapping
Elsewhere Maybe All Commands are Simple
Excellent Manuals Are Clearly Suppressed
Emacs May Alienate Clients and Supporters
Except by Middle Aged Computer Scientists
Extended Macros Are Considered Superfluous
Every Mode Accelerates Creation of Software
Each Manual's Audience is Completely Stupefied
Exceptionally Mediocre Algorithm for Computer Scientists
Easily Maintained with the Assistance of Chemical Solutions
Eradication of Memory Accomplished with Complete Simplicity  

如果只有一个单词，通常取每个章节的首字母：

cp CoPy
ln LiNk
ls LiSt
mv MoVe
rm ReMove

对于目录，通常使用前几个字母作为缩写：

bin BINaries
dev DEVices
etc ETCetera
lib LIBrary
var VARiable
proc PROCesses
sbin Superuser BINaries
tmp TeMPorary
usr Unix Shared Resources

这种缩写的其它情况

diff DIFFerences
cal CALendar
cat CATenate
ed EDitor
exec EXECute
tab TABle
regexp REGular EXPression

如果某种缩写比较深入人心，例如mesg代表message，在新的复合缩写中，将沿用这种缩写方式

dmesg Disgnostic MESsaGe
sed Stream EDitor
stty Set TTY
fstab FileSystem TABle
passwd PASSWorD

有些缩写中，第一个字母g，代表GNU

awk Aho Weiberger and Kernighan
gawk GNU AWK
gpg GNU Privacy Guard
grep GNU Regular Expression Print
egrep Extended GREP

定义中包含自身缩写，如 GNU：

GNU’s Not Unix

使用这个定义来解释定义中的缩写：

(GNU’s Not Unix)’s Not Unix

这意味着它是可以无限递归的：

(((((GNU’s Not Unix)’s Not Unix)’s Not Unix)’s Not Unix)’s Not Unix)’s Not Unix ……