命令行一些技巧：
*
表示任意字符（也可以无字符）
?
任意一个单字符
[a-z]
包含一个字符范围中的任一字符
[^a-z]
不包含此范围的字符
Tab键
补齐命令名称或其他名称
history
重新输入以前执行过的指令
!+序号
^
替代上个命令中的某一段字符
如^2^1 将上个命令中的1替换为2
~
进入家目录(home directory)
~root
~user1
$
变量名
如 echo $HOME
{}
排列组合
a{a,b}=aa,ab
`` or $()
优先执行的命令
echo "Hostname: `hostname`"
$[]
进行数学计算
echo $[$a + $b]
\
后面的命令接着前面的
"
禁止所有特殊资源的功能，除了$ \ ` !
’
禁止所有特殊资源的功能
+. or +.
补齐上个命令的最后一个参数
set -o/+o vi
切换编辑模式
常用命令：
date
cal: calendar
pwd: parent working directory
cd: change directory
ls: list directory contents
cp: copy files and directories
mv: move and/or rename files and directories
rm: remove files
touch: create empty files or update file timestamps
mkdir: make a directory
rmdir: remove an empty directory
file: check file type
cat: view an entire text file
less: view text page by page
cut: display specific columns of file data
sort: sort text to standard out - original file unchanged
chmod: change access modes
df: report disk space usage(free)
du: report disk space usage(used)
tar: create/extract an archive
gzip: compress
bzip: compress
gunzip: extract
bunzip: extract
passwd: change password
su: start a new shell as a different user
sed: search and replace
head: display first few lines(default 10 lines) of text in a file
tail: display last few lines(default 10 lines) of text in a file
wc: “count lines, words and characters”
uniq: “remove successive, duplicate lines in a file”
paste: paste files together
tr: character translator
diff: version comparison
sdiff: version comparison
aspell: spell checking
expand: expand tabs into spaces
fmt: reformat text into paragraphs
pr: reformat text for printing
top: display snapshot of processes
vmstat: report virtual memory stats
free: summary of system memory usage
renice: change priority of a process
kill: send system signal to a process
fdisk: create partitions
partprobe: reinitialize the kernel in memory of the partition table
mke2fs: filesystem creation
lsattr: display file attributes
chattr: change file attributes
ln: linkname
alias: create shortcuts to commands
whoami: find out who you are
groups: find out what groups you belong to
id: find out what groups you belong to
users: find out who is logged in
who: find out who is logged in
w: find out who is logged in
last: login/reboot history