what does this linux command do: "cd !!:1"

Question

In linux command cd, after make a dir, I can use "cd !!:1" to enter it, but what exactly does !!:1 mean, I can't search it by google, because it include special chars.

Answer 1

That will change directory to the first argument of the previous command

For example

% ls foo bar
% cd !!:1

is equivalent to

% ls foo bar
% cd foo

Also !!:0 gives you the actual command (less arguments), !!:2 the second argument, !!:$ the last argument, and !! the whole command line.