模式匹配

1. 括号的分组标签,最多9组,依次为1...9

sed -r 's/^(address)/#1/' /etc/network/interfaces
sed -r s/^(address)/#\1/ /etc/network/interfaces

2. 用&代表匹配到的内容

sed -r 's/^address/#&/' /etc/network/interfaces

原文地址:https://www.cnblogs.com/eric-geoffrey/p/4835647.html