/usr/share/vim/vim80/macros/matchit.vim is in vim-runtime 2:8.0.1453-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | " Load the matchit package.
" For those users who were loading the matchit plugin from here.
if 1
packadd matchit
endif
|