读取文件,显示行号 nl -a.txt brace expansion 花括号扩展 echo a{A{1,2},B{3,4}}b mkdir {2009...2011}-0{1...9} {2009...2011}-{10...12} mkdir {2009..2011}-0{1..9} {2009..2011}-{10..12} $ echo this is echo this is echo $ echo * 当前目录下所有文件名 rename Rename SOURCE to DEST,…