替換文本段落

Question

如何使用shell命令（SED或AWK）來替換一個段落在文件如下所示：

bala bala ba1 
balabala. 
leave me here. 

this paragraph 
yes, I'm going 
to be replaced 

The rest contains 
should not be replaced. 

更換後：

bala bala ba1 
balaba. 
leave me here. 

New contains, 
I'm replacement! 

The rest contains 
should not be replaced. 

我聲明包含在變量$OLD中的原始數據，並將新數據包含在另一個變量$NEW中。

Answer 1

假設您擁有一個包含新老段落，變量在

$ echo "$old" 
this paragraph 
yes, I'm going 
to be replaced 

和

$ echo "$new" 
New contains, 
I'm replacement! 

您可以讀取該文件（假設這就是所謂的infile）成猛砸變量和使用參數擴展：

$ contents=$(< infile) 
$ echo "${contents/$old/$new}" 
bala bala ba1 
balabala. 
leave me here. 

New contains, 
I'm replacement! 

The rest contains 
should not be replaced. 

要就地更改文件：

echo "${contents/$old/$new}" > infile.tmp && mv infile.tmp infile