in reply to On zero-width negative lookahead assertions

there are two errors in the code:

You are searching the match and Perl find it for you looking through all possible combinations

Replies are listed 'Best First'.
Re^2: On zero-width negative lookahead assertions
by bronto (Priest) on Sep 10, 2004 at 14:21 UTC
    @ and . must be backslashed

    Backslashed: still matches too much

    your \s* allows the regexp to match when \s* matches empty string

    I know it, I expressely want to match 0 or more spaces before line end


    In theory, there is no difference between theory and practice. In practice, there is.

      Note the difference: perl -ne '/^root:(?!\s*admin\@somewhere\.here)/ and print' alliases