1 Reply Latest reply on Sep 28, 2014 9:04 AM by [Jongware]

    grep:why ([[:blank:]])(?!(.+>)) is right,but (?<!(.+<)) ([[:blank:]]) is wrong?

    喜狼_edny Level 1

      For example:

      My  book's name is < The spirit of God>.If it be faithful to god, it will reflect his light, and will, eventually, return unto him.

      xbean.cs.ccu.edu.tw

       

      This is just one example, I want to say is:


      why (?!(.+>)) is right when it is in the back,


      but (?<!(.+<)) is wrong when it is In the front


      and why: (?<=(.{4})) is right,   but (?<=(.{4,16})) is error expression@