上古神器sed命令（上）

上古神器sed命令（上）

上古神器sed命令上

测试文档peopletxt

s参数

1替换

2指定某些行替换

3替换每一行中的第2个小写s成大写S

i参数

1直接通过sed修改原文加选项 -i

g参数会匹配里面所有内容

1替换每一行中的所有的小写s成大写S

2替换每一行中的第2个以后的小写s成大写S

测试文档：(people.txt)

Jack    is 18-year old, he comes from US.
Mike    is 16-year old, he comes from Canada.
Chen    is 21-year old, he comes from China.
Lau     is 18-year old, he comes from HongKong.
Michael is 20-year old, he comes from UK.
Phoebe  is 18-year old, she comes from Australie.

s参数

“s/old/new/”	“2s/-year/years/”	“2,5s/-year/years/”
首次出现的更改	第2行的”-year”改成” years”首次出现更改	2到5行修改

1，替换：

例如，将首次出现的”-year”改成” years”，第二次出现的或第三次出现的不用改：

sed  "s/-year/years/" people.txt

Jack    is 18years old, he comes from US.
Mike    is 16years old, he comes from Canada.
Chen    is 21years old, he comes from China.
Lau     is 18years old, he comes from HongKong.
Michael is 20years old, he comes from UK.
Phoebe  is 18years old, she comes from US.

2，指定某些行替换：

例如，将第2行的”-year”改成” years”，(只更改第二行)首次出现更改：

sed  "2s/-year/years/" people.txt

Jack    is 18-year old, he comes from US.
Mike    is 16years old, he comes from Canada.
Chen    is 21-year old, he comes from China.
Lau     is 18-year old, he comes from HongKong.
Michael is 20-year old, he comes from UK.
Phoebe  is 18-year old, she comes from Australie.

再如，将第2至5行的”-year”改成” years”：

sed  "2,5s/-year/years/" people.txt

Jack    is 18-year old, he comes from US.
Mike    is 16years old, he comes from Canada.
Chen    is 21years old, he comes from China.
Lau     is 18years old, he comes from HongKong.
Michael is 20years old, he comes from UK.
Phoebe  is 18-year old, she comes from Australie.

3，替换每一行中的第2个小写s成大写S：

sed  "s/s/S/2" people.txt

i参数

1，直接通过sed修改原文，加选项 -i：

sed  -i "2s/-year/years/" people.txt

注意：sed缺省状态下不会修改原文

g参数(会匹配里面所有内容)

1，替换每一行中的所有的小写s成大写S：

sed  "s/s/S/g" people.txt

Jack    iS 18-year old, he comeS from US.
Mike    iS 16-year old, he comeS from Canada.
Chen    iS 21-year old, he comeS from China.
Lau     iS 18-year old, he comeS from HongKong.
Michael iS 20-year old, he comeS from UK.
Phoebe  iS 18-year old, She comeS from AuStralie.

注意：g的意思是一行中所有的匹配项，否则缺省只会匹配第一个s

2，替换每一行中的第2个以后的小写s成大写S：

sed  "s/s/S/2g" people.txt

Jack    is 18-year old, he comeS from US.
Mike    is 16-year old, he comeS from Canada.
Chen    is 21-year old, he comeS from China.
Lau     is 18-year old, he comeS from HongKong.
Michael is 20-year old, he comeS from UK.
Phoebe  is 18-year old, She comeS from AuStralie.