命令：
a
alias; unalias;
b
basename;
c
cat; clock -s; clock -w; cal; cp; chpasswd; chown; chmod; chgrp; chattr; ahcge; chfn; chsh; cut;
d
dirname; diff;
e
enable;
f
free -h; file;
g
getenforce; groupadd; groupmod; groupdel; getfacl; getent passwd; gpasswd; groups; groupmems; grpck; grep; gcc;
h
hash; hostname; help; history; hexdump; head;
i
init 3 5 0关机 6重启; ifconfig; iptabled -nvl;
j
k
l
lsb_release -a; lsblk; ln -s; lsattr; less;
m
mandb; man；mv; more;
n
ntpdate; newusers; newgrp; netstat; nl; nmap;
o
openssl rand -base64 9;
p
pstree; pidof; pwck; pwcov; pwuncov; paste; patch;
q
r
runlevel; rename; rev;
s
source ;sleep ;screen; shutdown; stat; setfacl; su; su -; sort; scp;
t
tty; type; touch; tr; tail;
u
uname -r; unalias; useradd; usermod; userdel; umaek; uniq;
v
vim; vidir; vipw; vigrp;
w
who; whoami;who -r; whatis; where; which; wc;
x
xargs;
y
z