linux中给每一行数据添加索引

1、测试数据

[root@centos7pc1 test3]# ls
a.txt
[root@centos7pc1 test3]# cat a.txt
ddfg uujj
mmkk xxuu
zzdd mmuh
zzvv ddee

 

2、sed实现

[root@centos7pc1 test3]# ls
a.txt
[root@centos7pc1 test3]# cat a.txt
ddfg uujj
mmkk xxuu
zzdd mmuh
zzvv ddee
[root@centos7pc1 test3]# sed = a.txt   ## 直接添加索引
1
ddfg uujj
2
mmkk xxuu
3
zzdd mmuh
4
zzvv ddee

 

[root@centos7pc1 test3]# ls
a.txt
[root@centos7pc1 test3]# cat a.txt
ddfg uujj
mmkk xxuu
zzdd mmuh
zzvv ddee
[root@centos7pc1 test3]# sed = a.txt
1
ddfg uujj
2
mmkk xxuu
3
zzdd mmuh
4
zzvv ddee
[root@centos7pc1 test3]# sed = a.txt  | sed '2~2G'
1
ddfg uujj

2
mmkk xxuu

3
zzdd mmuh

4
zzvv ddee

[root@centos7pc1 test3]# sed = a.txt  | sed '2~2G' | sed '3~3G'
1
ddfg uujj


2
mmkk xxuu


3
zzdd mmuh


4
zzvv ddee

 

3、awk + sed实现

[root@centos7pc1 test3]# ls
a.txt
[root@centos7pc1 test3]# cat a.txt
ddfg uujj
mmkk xxuu
zzdd mmuh
zzvv ddee
[root@centos7pc1 test3]# awk '{print NR, $0}' a.txt
1 ddfg uujj
2 mmkk xxuu
3 zzdd mmuh
4 zzvv ddee
[root@centos7pc1 test3]# awk '{print NR, $0}' a.txt | sed 's/ /\n/'
1
ddfg uujj
2
mmkk xxuu
3
zzdd mmuh
4
zzvv ddee

 

4、cat + sed实现

[root@centos7pc1 test3]# ls
a.txt
[root@centos7pc1 test3]# cat a.txt
ddfg uujj
mmkk xxuu
zzdd mmuh
zzvv ddee
[root@centos7pc1 test3]# cat -n a.txt
     1  ddfg uujj
     2  mmkk xxuu
     3  zzdd mmuh
     4  zzvv ddee
[root@centos7pc1 test3]# cat -n a.txt | sed 's/^[\t ]*//'
1       ddfg uujj
2       mmkk xxuu
3       zzdd mmuh
4       zzvv ddee
[root@centos7pc1 test3]# cat -n a.txt | sed 's/^[\t ]*//' | sed 's/\t/\n/'
1
ddfg uujj
2
mmkk xxuu
3
zzdd mmuh
4
zzvv ddee