1.1軟連接
題；
-ln –s oldboy.txt oldboy_soft_link
cat oldboy_soft_link
I am oldboy
1.2字符（character）/塊（block)設(shè)備文件
以c開(kāi)頭的就是字符設(shè)備,貓等串口設(shè)備
以b開(kāi)頭的就是塊設(shè)備硬盤(pán)贤笆、光驅(qū)等都屬于塊設(shè)備
1.3套接口（socket）文件
以s開(kāi)頭
.sock文件也是一類(lèi)特殊的文件，這類(lèi)文件通常用在網(wǎng)絡(luò)之間摸航，進(jìn)行數(shù)據(jù)連接，如：我們可以啟動(dòng)一個(gè)程序來(lái)監(jiān)聽(tīng)客戶(hù)端的請(qǐng)求，客戶(hù)端可以通過(guò)套接字來(lái)進(jìn)行數(shù)據(jù)通信。
用于進(jìn)程之間通信的文件竭宰。
[root@oldboyedu ~]# which cp
alias cp='cp -i'
?????? /usr/bin/cp
[root@oldboyedu ~]# which ls
alias ls='ls --color=auto'
?????? /usr/bin/ls
[root@oldboyedu ~]# which ip
/usr/sbin/ip
1.4? ? path變量作用
命令行執(zhí)行命令會(huì)從PATH 對(duì)應(yīng)的路徑中查找命令，
PATH 對(duì)應(yīng)的路徑中沒(méi)有這個(gè)命令就會(huì)報(bào)command not found
[root@oldboyedu ~]# ff
-bash: ff: command not found
[root@oldboyedu ~]# cd /usr/local/sbin
[root@oldboyedu /usr/local/sbin]# vim ff
[root@oldboyedu /usr/local/sbin]# cat ff
echo $1
[root@oldboyedu /usr/local/sbin]# chmod +xff
[root@oldboyedu ~]# fff
-bash: fff: command not found
[root@oldboyedu ~]# ff
[root@oldboyedu ~]# ff oldboy
oldboy
[root@oldboyedu ~]# ff oldgirl
oldgirl
[root@oldboyedu ~]# echo oldgirl
oldgirl
[root@oldboyedu ~]# which ff
/usr/local/sbin/ff
1.5whereis：顯示命令份招、源碼切揭、說(shuō)明文檔等的路徑
locate:[root@oldboyedu ~]# whereis -b cp
cp: /usr/bin/cp
locate：快速定位文件路徑
locate查找文件路徑，是從數(shù)據(jù)庫(kù)A（/var/lib/mlocate/mlocate.db）里查詢(xún)
更新A數(shù)據(jù)庫(kù)用updatedb命令
C7默認(rèn)沒(méi)安裝脾还，不要學(xué)了
yum provides locate #《==查看命令對(duì)應(yīng)的軟件包
yum install mlocate -y
[root@oldboyedu ~]# locate cp
locate: can not stat ()`/var/lib/mlocate/mlocate.db': No such file or directory
[root@oldboyedu ~]# updatedb
[root@oldboyedu ~]# locate cp
/boot/grub2/i386-pc/acpi.mod
/boot/grub2/i386-pc/cpio.mod
1.6 find：查找目錄下的文件
查找原理：磁盤(pán)遍歷，速度慢入愧。
[root@oldboyedu ~]# find ~????? -name???"oldboy.txt"
???????????????????????? 路徑?名字參數(shù)? 具體文件
/root/oldboy.txt
練習(xí)：從根下查找ifcfg-eth0網(wǎng)卡文件
[root@oldboyedu ~]# find / -name"ifcfg-eth0"
/etc/sysconfig/network-scripts/ifcfg-eth0
模糊查找 *表示所有
[root@oldboyedu ~]# find / -name "*y*"
按文件類(lèi)型查找-type
[root@oldboyedu ~]# find / -type f -name"oldboy*"
??????-type c
????????????? File is of type c:
????????????? b????? block (buffered) special
????????????? c? ? ?character (unbuffered) special
????????????? d????? directory
???? ?????????p?????named pipe (FIFO)
????????????? f????? regular file
????????????? l????? symbolic link; this is never true if the-L option or the -follow
find / -type d -name "oldboy*"
這里的類(lèi)型和名字是取交集鄙漏，兩條件都滿(mǎn)足。默認(rèn)是交集棺蛛，相當(dāng)于有個(gè)-a
如果取并集即或者用-o分割查找的項(xiàng)
find / -type d -o -name "oldboy*"
1.7 xargs分組
[root@oldboyedu /data]# echo {1..10}>test.txt
[root@oldboyedu /data]# cat test.txt
1 2 3 4 5 6 7 8 9 10
[root@oldboyedu /data]# xargs -n 3
1 2 3
4 5 6
7 8 9
10
[root@oldboyedu /data]# xargs -n 4
1 2 3 4
5 6 7 8
9 10
[root@oldboyedu /data]# xargs -n 5
1 2 3 4 5
6 7 8 9 10
-d 指定分隔符怔蚌，不指定默認(rèn)是空格
[root@oldboyedu /data]# xargs-d"." -n2
a b
c d
[root@oldboyedu /data]# xargs -n2
a.b.c.d
[root@oldboyedu /data]# cat test.txt
a.b.c.d
[root@oldboyedu /data]# echo"Oldboy" >test.txt
[root@oldboyedu /data]# echo"Oldgirl" >>test.txt
[root@oldboyedu /data]# echo"Oldboedu" >>test.txt
[root@oldboyedu /data]# echo"Oldboyedu" >>test.txt
[root@oldboyedu /data]# cat test.txt
Oldboy
Oldgirl
Oldboedu
Oldboyedu
[root@oldboyedu /data]# cat test.txt|grep"boy"
Oldboy
Oldboyedu
[root@oldboyedu /data]# grep"boy" test.txt
Oldboy
Oldboyedu
[root@oldboyedu /data]# find /data -typef|xargs rm -f
[root@oldboyedu /data]# ll
total 0
drwxr-xr-x. 2 root root 6 Mar 14 10:40 a
drwxr-xr-x. 2 root root 6 Mar 14 10:40 b
drwxr-xr-x. 2 root root 6 Mar 14 10:40 c
drwxr-xr-x. 2 root root 6 Mar 14 10:40 d
[root@oldboyedu /data]# toucholdboy{1..5}.txt
[root@oldboyedu /data]# ls
a?b? c? d?oldboy1.txt? oldboy2.txt? oldboy3.txt?oldboy4.txt? oldboy5.txt
[root@oldboyedu /data]# find /data -type f-exec rm -f {} \;
[root@oldboyedu /data]# ls
a?b? c? d
find /data -type f -exec rm -f {} \;
相當(dāng)于
rm -f oldboy1.txt
rm -f oldboy2.txt
rm -f oldboy3.txt
效率低。
find /data -type f|xargs rm -f
只是一條命令
rm -f oldboy1.txt oldboy2.txt oldboy3.txt
效率高
find /data -type f|rm -f
相當(dāng)于：
find /data -type f
rm -f
1.8 data -s
[root@oldboyedu /data]# date -s"2020/10/1 00:00:00"
Thu Oct?1 00:00:00 CST 2020
[root@oldboyedu /data]# date
Thu Oct?1 00:00:03 CST 2020
[root@oldboyedu /data]# clock -w
[root@oldboyedu /data]# date +%F
2020-10-01
[root@oldboyedu /data]# date +%Y?? #year年
2020
[root@oldboyedu /data]# date +%y?? #year年
20
[root@oldboyedu /data]# date +%m?? #month月
10
[root@oldboyedu /data]# date +%d?? #day日
01
[root@oldboyedu /data]# date +%H?? #hour時(shí)
00
[root@oldboyedu /data]# date +%M?? #minute分
02
[root@oldboyedu /data]# date +%S?? #second秒
46
[root@oldboyedu /data]# date +%Y-%m-%d
2020-10-01
[root@oldboyedu /data]# date +%F
2020-10-01
[root@oldboyedu /data]# date +%H:%M:%S
00:04:29
[root@oldboyedu /data]# date
Thu Oct?1 00:04:38 CST 2020
[root@oldboyedu /data]# date +%F -d"-1day"
2020-09-30
[root@oldboyedu /data]# date +%F -d"+1day"
2020-10-02
[root@oldboyedu /data]# date +%F -d"+1month"
2020-11-01
[root@oldboyedu /data]# date +%F -d"+1Y"
date: invalid date ‘+1Y’
[root@oldboyedu /data]# date +%F -d"+1year"
2021-10-01
- 過(guò)去
+ 未來(lái)
[root@oldboyedu /data]# date+"%Y-%m-%d %H:%M:%S"
2020-10-01 00:09:36
[root@oldboyedu /data]# date +"%F%T"
2020-10-01 00:09:39
打包壓縮
打包筐放文件壓縮體積降低
文件壓縮旁赊，大小會(huì)降低桦踊。
1.9 tar壓縮 解壓
例子：
[root@oldboyedu ~]# mkdir /data
[root@oldboyedu ~]# cd /data
[root@oldboyedu /data]# touch {1..5}.txt
[root@oldboyedu /data]# ls
1.txt?2.txt? 3.txt? 4.txt?5.txt
[root@oldboyedu /data]# cd ..
[root@oldboyedu /]# tar zcvf/opt/data.tar.gz ./data
./data/
./data/1.txt
./data/2.txt
./data/3.txt
./data/4.txt
./data/5.txt
查看壓縮包里的內(nèi)容：-t
[root@oldboyedu /]# tar tf /opt/data.tar.gz
./data/
./data/1.txt
./data/2.txt
./data/3.txt
./data/4.txt
./data/5.txt
解壓：
[root@oldboyedu /opt]# tar zxvf data.tar.gz
./data/
./data/1.txt
./data/2.txt
./data/3.txt
./data/4.txt
./data/5.txt
[root@oldboyedu /opt]# ls
data?data.tar.gz
[root@oldboyedu /opt]# ls data
1.txt?2.txt? 3.txt? 4.txt?5.txt
[root@oldboyedu /opt]# tar xf data.tar.gz
[root@oldboyedu /opt]# tar xf data.tar.gz-C /tmp/
[root@oldboyedu /opt]# ls /tmp/data
1.txt?2.txt? 3.txt? 4.txt?5.txt
