How do I trigger wildcard filename completion from inside a custom key mapping in Vim?

Explanation

The wildchar option (default <Tab>) triggers wildcard completion interactively on the command line. But <Tab> embedded directly in a mapping is awkward — it fires at map-definition time, not when the mapping runs. The wildcharm option solves this: it designates a separate character that triggers the same completion, and that character can safely appear in mapping definitions.

How it works

• :set wildcharm=<C-z> — designate <C-z> (Ctrl+Z) as the completion trigger for mappings
• Now you can embed <C-z> in any nnoremap or cnoremap to fire the wildmenu
• Useful for creating mappings that drop into a command with completion already active

Example

Add to your vimrc:

set wildcharm=<C-z>
nnoremap <leader>b :buffer <C-z>
nnoremap <leader>e :edit **/*<C-z>

With wildmenu enabled, pressing <leader>b immediately opens :buffer with the completion menu showing all open buffers.

:buffer [buffer1] buffer2 buffer3

Pressing <leader>e opens :edit **/* and immediately shows a fuzzy file picker.

Tips

• wildcharm must differ from wildchar — using <C-z> avoids any conflicts since <C-z> (suspend) is unlikely to be used in mappings
• Combine with :set wildmenu and :set wildmode=list:longest,full for the best completion experience
• The character can be any unused key — <C-z> is the traditional recommendation in Vim's own help
• This also works in cnoremap for building smart command-line helpers