All folds open when opening a file
From Vim Tips Wiki
created October 1, 2004 · complexity basic · author Pim Snel · version 6.0
When you set
foldmethod to something like
syntax, which defines folds as soon as you open the file, all folds are closed by default. If you set the
foldlevel to a high setting, files are always loaded with opened folds. For example, you could put the settings below in your
set foldmethod=indent set foldlevel=20
This is not ideal, however, as the
foldlevel option is local to the window, and additionally gets modified every time you use a command that adjusts the fold level, like
zr, and their friends.
A better method is to set the
foldlevel whenever you load a buffer into a window. You could use autocommands for this, but there is a built-in option that does this for you automatically:
This is much closer to an optimal solution, but one problem remains: even with the
foldlevelstart option, it will take several iterations of the
zm command to hide any of a file if you have set the
foldlevel high enough. To fix this, you need to use autocmds. For example, to open all folds for a list of file types, but only up to the maximum fold level so that
zm and related commands work right away, you could do the following:
" Note, perl automatically sets foldmethod in the syntax file autocmd Syntax c,cpp,vim,xml,html,xhtml setlocal foldmethod=syntax autocmd Syntax c,cpp,vim,xml,html,xhtml,perl normal zR
Tweak the event and filetypes matched to your liking.
You could use a combination of this method and the
foldlevelstart option to get just enough fold levels open on certain filetypes, but default to having them all open for files which are not of one of your chosen types.
 See also
- Folding presents an overview of how to use folding