# awk ‘条件1{动作1} 条件2{动作2}…’ 文件名
条件（ Pattern）：
一般使用关系表达式作为条件
x > 10 判断变量 x是否大于10
x>=10 大于等于
x<=10 小于等于
动作（ Action）：
格式化输出
流程控制语句
文本信息：vim score.txt
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ID Name PHP Linux MySQL Average1 Liming 82 95 86 87.662 Sc 74 96 87 85.663 Gao 99 83 93 91.661、 输出score.txt每行内容，第2行+\t+第6行+\n
printf行尾不输出换行；print行为输出换行
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[root@V2 tmp]# cat score.txt
D Name PHP Linux MySQL Average1 Liming 82 95 86 87.662 Sc 74 96 87 85.663 Gao 99 83 93 91.66[root@V2 tmp]# awk '{printf $2 "\t" $6 "\n"}' score.txt
Name AverageLiming 87.66Sc 85.66Gao 91.662、输出df第1,3行内容
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[root@V2 tmp]# df -h
Filesystem Size Used Avail Use% Mounted on/dev/mapper/vg_v2-lv_root 36G 5.0G 29G 15% /
tmpfs 931M 72K 931M 1% /dev/shm
/dev/sda1 485M 40M 421M 9% /boot
[root@V2 tmp]# df -h | awk '{print $1 "\t" $3}'
Filesystem Used/dev/mapper/vg_v2-lv_root 5.0G
tmpfs 72K/dev/sda1 40M
3、输出下面内人中的1
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df -h|grep tmpfs|awk '{print $5}'|cut -d "%" -f 1
4、BEGIN
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[root@V2 tmp]# awk 'BEGIN{print "这里是开始前输出"}{printf $2 "\t" $6 "\n"}' score.txt
这里是开始前输出Name AverageLiming 87.66Sc 85.66Gao 91.665、END
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[root@V2 tmp]# awk 'BEGIN{print "这里是开始前输出"}END{print "这里是结束输出"}{printf $2 "\t" $6 "\n"}' score.txt
这里是开始前输出Name AverageLiming 87.66Sc 85.66Gao 91.66这里是结束输出6、FS设置分隔符
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[root@V2 tmp]# cat /etc/passwd | grep "/bin/bash" | awk 'BEGIN {FS=":"} {printf $1 "\t" $3 "\n"}'
root 0chenzhi 500mysql 27[root@V2 tmp]# cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
nobody:x:99:99:Nobody:/:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
usbmuxd:x:113:113:usbmuxd user:/:/sbin/nologin
vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin
rpc:x:32:32:Rpcbind Daemon:/var/cache/rpcbind:/sbin/nologin
rtkit:x:499:497:RealtimeKit:/proc:/sbin/nologin
avahi-autoipd:x:170:170:Avahi IPv4LL Stack:/var/lib/avahi-autoipd:/sbin/nologin
abrt:x:173:173::/etc/abrt:/sbin/nologin
rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin
nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/sbin/nologin
haldaemon:x:68:68:HAL daemon:/:/sbin/nologin
gdm:x:42:42::/var/lib/gdm:/sbin/nologin
ntp:x:38:38::/etc/ntp:/sbin/nologin
apache:x:48:48:Apache:/var/www:/sbin/nologin
saslauth:x:498:76:"Saslauthd user":/var/empty/saslauth:/sbin/nologin
postfix:x:89:89::/var/spool/postfix:/sbin/nologin
pulse:x:497:496:PulseAudio System Daemon:/var/run/pulse:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin
tcpdump:x:72:72::/:/sbin/nologin
chenzhi:x:500:500:chenzhi:/home/chenzhi:/bin/bash
mysql:x:27:27:MySQL Server:/var/lib/mysql:/bin/bash
[root@V2 tmp]# cat /etc/passwd | grep "/bin/bash" | awk 'BEGIN {FS=":"} {printf $1 "\t" $3 "\n"}'
root 0chenzhi 500mysql 277、逻辑运算
grep -v Name 删除包含内容为"Name"的行
awk '$6 >= 87 {printf $2 "\n" } 计算第6行大于87的
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[root@V2 tmp]# cat score.txt
D Name PHP Linux MySQL Average1 Liming 82 95 86 87.662 Sc 74 96 87 85.663 Gao 99 83 93 91.66[root@V2 tmp]# cat score.txt | grep -v Name | awk '$6 >= 87 {printf $2 "\n" }'
LimingGao