请教sed命令合并的问题

insnowind

请问
sed -n '/^AAA/p'  urfile | sed 's/^AAA//g'
如何简化一下。

waker

sed -n '/^AAA/s///p'  urfile

insnowind

回复 2# waker


   再次请教一下 s/// 这里是怎么操作的，sed是如何把前面匹配到的串作为被替换的串，从哪里可以找到这种用法，多谢~

waker

回复 3# insnowind

gnu sed官方文档里就有吧

1. 
   
2. /regexp/
   
3.     This will select any line which matches the regular expression regexp. If regexp itself includes any / characters, each must be escaped by a backslash (\).
   
4. 
   
5.     The empty regular expression ‘//’ repeats the last regular expression match (the same holds if the empty regular expression is passed to the s command). Note that modifiers to regular expressions are evaluated when the regular expression is compiled, thus it is invalid to specify them together with the empty regular expression.
   

复制代码

http://www.gnu.org/software/sed/manual/html_node/Addresses.html