linux 中grep命令匹配指定长度的字符串

 

1、

root@PC1:/home/test# ls
a.txt
root@PC1:/home/test# cat a.txt                 ## 测试数据
d xaa
c xaaa
d xaaaa
e xaaaaa
f xaaaaaa
d dff gfgfgf
e dfgdg gfdgedr
d dfef fcgfg
root@PC1:/home/test# grep -E -w "[^[:space:]]{3}" a.txt    ## 长度为3
d xaa
d dff gfgfgf
root@PC1:/home/test# grep -E -w "[^[:space:]]{4}" a.txt     ## 长度为4
c xaaa
d dfef fcgfg
root@PC1:/home/test# grep -E -w "[^[:space:]]{5}" a.txt
d xaaaa
e dfgdg gfdgedr
d dfef fcgfg
root@PC1:/home/test# grep -E -w "[^[:space:]]{7}" a.txt     ## 长度为7
f xaaaaaa
e dfgdg gfdgedr

 

 

2、awk实现

root@PC1:/home/test# ls
a.txt
root@PC1:/home/test# cat a.txt
d xaa
c xaaa
d xaaaa
e xaaaaa
f xaaaaaa
d dff gfgfgf
e dfgdg gfdgedr
d dfef fcgfg
root@PC1:/home/test# awk '{for(i = 1; i <= NF; i++) {if(length($i) == 3) printf("%s\n", $0)}}' a.txt     ## 输出长度为3的行
d xaa
d dff gfgfgf
root@PC1:/home/test# awk '{for(i = 1; i <= NF; i++) {if(length($i) == 4) printf("%s\n", $0)}}' a.txt     ## 长度为4
c xaaa
d dfef fcgfg
root@PC1:/home/test# awk '{for(i = 1; i <= NF; i++) {if(length($i) == 5) printf("%s\n", $0)}}' a.txt     ## 长度为5
d xaaaa
e dfgdg gfdgedr
d dfef fcgfg