commit https://github.com/vim/vim/commit/aa23b379421aa214e6543b06c974594a25799b09 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Sep 8 18:46:31 2015 +0200 patch 7.4.858 Problem: It's a bit clumsy to execute a command on a list of matches. Solution: Add the ":ldo", ":lfdo", ":cdo" and ":cfdo" commands. (Yegappan Lakshmanan)

Tests for writefile()

STARTTEST
:source small.vim
:%delete _
:let f = tempname()
:call writefile(["over","written"], f, "b")
:call writefile(["hello","world"], f, "b")
:call writefile(["!", "good"], f, "a")
:call writefile(["morning"], f, "ab")
:call writefile(["", "vimmers"], f, "ab")
:bwipeout!
:$put =readfile(f)
:1 delete _
:w! test.out
:qa!
ENDTEST