ls：list(列出目录内容)
cd：Change Directory（改变目录）
su:switch user 切换用户
rpm:redhat package manager 红帽子打包管理器
pwd:print work directory 打印当前目录显示出当前工作目录的绝对路径
ps: process status(进程状态，类似于 windows 的任务管理器)
常用参数：－auxf
ps -auxf 显示进程状态
df: disk free 其功能是显示磁盘可用空间数目信息及空间结点信息。换句话说，就是报告在任何安装的设备或目录中，还剩多少自由的空间。
rpm：即 RedHat Package Management，是 RedHat 的发明之一
rmdir：Remove Directory（删除目录）
rm：Remove（删除目录或文件）
cat: concatenate 连锁 cat file1 file2>>file3把文件1和文件2的内容联合起来放到 file3中
insmod: install module,载入模块
ln -s : link -soft 创建一个软链接，相当于创建一个快捷方式
mkdir：Make Directory(创建目录
touch
man: Manual
pwd：Print working directory
su：Swith user
cd：Change directory
ls：List files
ps：Process Status
mkdir：Make directory
rmdir：Remove directory
mkfs: Make file system
fsck：File system check
cat: Concatenate
uname: Unix name
df: Disk free
du: Disk usage
lsmod: List modules
mv: Move file
rm: Remove file
cp: Copy file
ln: Link files
fg: Foreground
bg: Background
chown: Change owner
chgrp: Change group
chmod: Change mode
umount: Unmount
dd: 本来应根据其功能描述“Convert an copy”命名为“cc”，但“cc”已经被用以代表“C Complier”，所以命名为“dd”
tar：Tape archive
ldd：List dynamic dependencies
insmod：Install module
rmmod：Remove module
lsmod：List module
文件结尾的"rc"（如.bashrc、.xinitrc 等）：Resource configuration
Knnxxx / Snnxxx（位于 rcx.d 目录下）：K（Kill）；S(Service)；nn（执行顺序号）；xxx（服务标识）
.a（扩展名 a）：Archive，static library
.so（扩展名 so）：Shared object，dynamically linked library
.o（扩展名 o）：Object file，complied result of C/C++ source file
RPM：Red hat package manager
dpkg：Debian package manager
apt：Advanced package tool（Debian 或基于 Debian 的发行版中提供）
bin = BINaries
/dev = DEVices
/etc = ETCetera
/lib = LIBrary
/proc = PROCesses
/sbin = Superuser BINaries
/tmp = TeMPorary
/usr = Unix Shared Resources
/var = VARiable ?
FIFO = First In, First Out
GRUB = GRand Unified Bootloader
IFS = Internal Field Seperators
LILO = LInux LOader
MySQL = My 是最初作者女儿的名字，SQL = Structured Query Language
PHP = Personal Home Page Tools = PHP Hypertext Preprocessor
PS = Prompt String
Perl = "Pratical Extraction and Report Language" = "Pathologically Eclectic Rubbish Lister"
Python 得名于电视剧 Monty Python's Flying Circus
Tcl = Tool Command Language
Tk = ToolKit
VT = Video Terminal
YaST = Yet Another Setup Tool
apache = "a patchy" server
apt = Advanced Packaging Tool
ar = archiver
as = assembler
awk = "Aho Weiberger and Kernighan" 三个作者的姓的第一个字母
bash = Bourne Again SHell
bc = Basic (Better) Calculator
bg = BackGround
biff = 作者 Heidi Stettner 在 U.C.Berkely 养的一条狗,喜欢对邮递员汪汪叫。
cal = CALendar
cat = CATenate
cd = Change Directory
chgrp = CHange GRouP
chmod = CHange MODe
chown = CHange OWNer
chsh = CHange SHell
cmp = compare
cobra = Common Object Request Broker Architecture
comm = common
cp = CoPy
cpio = CoPy In and Out
cpp = C Pre Processor
cron = Chronos 希腊文时间
cups = Common Unix Printing System
cvs = Current Version System
daemon = Disk And Execution MONitor
dc = Desk Calculator
dd = Disk Dump
df = Disk Free
diff = DIFFerence
dmesg = diagnostic message
du = Disk Usage
ed = editor
egrep = Extended GREP
elf = Extensible Linking Format
elm = ELectronic Mail
emacs = Editor MACroS
eval = EVALuate
ex = EXtended
exec = EXECute
fd = file descriptors
fg = ForeGround
fgrep = Fixed GREP
fmt = format
fsck = File System ChecK
fstab = FileSystem TABle
fvwm = F*** Virtual Window Manager
gawk = GNU AWK
gpg = GNU Privacy Guard
groff = GNU troff
hal = Hardware Abstraction Layer
joe = Joe's Own Editor
ksh = Korn SHell
lame = Lame Ain't an MP3 Encoder
lex = LEXical analyser
lisp = LISt Processing = Lots of Irritating Superfluous Parentheses
ln = LiNk
lpr = Line PRint
ls = list
lsof = LiSt Open Files
m4 = Macro processor Version 4
man = MANual pages
mawk = Mike Brennan's AWK
mc = Midnight Commander
mkfs = MaKe FileSystem
mknod = MaKe NODe
motd = Message of The Day
mozilla = MOsaic GodZILLa
mtab = Mount TABle
mv = MoVe
nano = Nano's ANOther editor
nawk = New AWK
nl = Number of Lines
nm = names
nohup = No HangUP
nroff = New ROFF
od = Octal Dump
passwd = PASSWorD
pg = pager
pico = PIne's message COmposition editor
pine = "Program for Internet News & Email" = "Pine is not Elm"
ping = 拟声又 = Packet InterNet Grouper
pirntcap = PRINTer CAPability
popd = POP Directory
pr = pre
printf = PRINT Formatted
ps = Processes Status
pty = pseudo tty
pushd = PUSH Directory
pwd = Print Working Directory
rc = runcom = run command, rc 还是 plan9的 shell
rev = REVerse
rm = ReMove
rn = Read News
roff = RunOFF
rpm = RPM Package Manager = RedHat Package Manager
rsh, rlogin, rvim 中的 r = Remote
rxvt = ouR XVT
seamoneky = 我
sed = Stream EDitor
seq = SEQuence
shar = SHell ARchive
slrn = S-Lang rn
ssh = Secure SHell
ssl = Secure Sockets Layer
stty = Set TTY
su = Substitute User
svn = SubVersioN
tar = Tape ARchive
tcsh = TENEX C shell
tee = T (T 形水管接口)
telnet = TEminaL over Network
termcap = terminal capability
terminfo = terminal information
tex = τ
