sed/awk advance

$ echo test.file

[Group1]
cacheways = 19

[Group2]
cacheways = 19

$ ls test.sh

 FILE=test.file
2 # Set Group1 cacheways =
 sed -i -e '/\[Group1\]*/{$!{N;s/\(cacheways = \)\(.*\)/\11/}}' $FILE
 # Set Group2 cacheways =
 sed -i -e '/\[Group2\]*/{$!{N;s/\(cacheways = \)\(.*\)/\110/}}' $FILE

$ test.sh

ref：

【1】 sed疑难杂症：关于shell变量替换

awk

$ ip route get
1.0.0.0 via 10.0.0.1 dev ens3 src 10.0.0.14 uid
    cache
 
$ ip route get  | awk '{match($0, /.+src\s([.0-9]+)/, a);print a[1];exit}'
10.0.0.14

awk ip 正则表达式

awk match 用法

awk之match函数

awk正则表达式捕获

awk内置函数sub gensub gsub match等介绍

linux awk之gensub()函数详解