linux awk基本语法命令总结

一、基本用法

文本内容准备

2 this is a test
3 Are you like awk
This's a test
10 There are orange,apple,mongo

用法一：行匹配语句awk ‘'只能使用单引号

实例：每行按空格或TAB分割，输出文本中的1、4项

[root@master mnt]# cat log.txt |awk '{print $1,$4}'
2 a
3 like
This's 
10 orange,apple,mongo
格式化输出

[root@master mnt]# cat log.txt |awk '{printf "%-8s %-10s ",$1,$4}'
2 a
3 like
This's
10 orange,apple,mongo

用法二：-F，指定分隔符

[root@master mnt]# cat log.txt |awk -F ',' '{print $1,$2}'
2 this is a test 
3 Are you like awk 
This's a test 
10 There are orange apple

或者使用内建表量

[root@master mnt]# cat log.txt |awk 'BEGIN{FS=","} {print $1,$2}'
2 this is a test
3 Are you like awk
This's a test
10 There are orange apple

#使用多个分隔符，先使用空格分割，然后对分割结果再使用“，”分割

[root@master mnt]# cat log.txt |awk -F '[ ,]' '{print $1,$2,$5}'
2 this test
3 Are awk
This's a
10 There apple

用法三：awk -v #设置变量

[root@master mnt]# cat log.txt |awk -va=1 -vb=s -vc=w '{print $1,$1+a,$1b,$1c}'
2 3 2s 2w
3 4 3s 3w
This's 1 This'ss This'sw
10 11 10s 10w

[root@master mnt]# cat log.txt |awk -va=1 '{print $1,$1+a}'
2 3
3 4
This's 1
10 11

用法四：awk -f {awk脚本} {文件名}

过滤第一列大于2的行
[root@master mnt]# cat log.txt |awk '$1>2'
3 Are you like awk
This's a test
10 There are orange,apple,mongo
过滤第一列等于2的行

[root@master mnt]# cat log.txt |awk '$1==2 {print $1,$2}'
2 this

过滤第一列大于2并且第二列等于'Are'的行

[root@master mnt]# cat log.txt |awk '$1>2 && $2=="Are" {print $1,$2}'
3 Are

用法五：指定输出分割符

[root@master mnt]# cat log.txt |awk '{print $1,$2,$5}' OFS=";" 
2;this;test
3;Are;awk
This's;a;
10;There;

用法六：正则字符串匹配

输出第二列包含“th” ，并打印第二列与第四列
[root@master mnt]# cat log.txt  |awk '$2 ~ /th/ {print $2,$4}'
this a

~表示模式匹配。//中是匹配的字符串

用法七：忽略大小写

[root@master mnt]# cat log.txt |awk 'BEGIN{IGNORECASE=1} /THIS/ '
2 this is a test
This's a test

用法八：模式取反

输出第二列不包含"th"的行的第二列和第四列
[root@master mnt]# cat log.txt |awk '$2 !~ /th/ {print $2,$4}'
Are like
a 
There orange,apple,mongo
等同于

[root@master mnt]# cat log.txt |awk '!/th/ {print $2,$4}'
Are like
a
There orange,apple,mongo