ibuffer-map-lines

ibuffer-map-lines is a compiled Lisp function in `ibuffer.el'.

(ibuffer-map-lines FUNCTION &optional NOMODIFY GROUP)

Call FUNCTION for each buffer.
Set the ibuffer modification flag unless NOMODIFY is non-nil.

If optional argument GROUP is non-nil, then only call FUNCTION on
buffers in filtering group GROUP.

FUNCTION is called with two arguments:
the buffer object itself and the current mark symbol.