How do I duplicate every line in a buffer so each line appears twice in place?
:g/^/t.
The command :g/^/t.
Category: command-line
How do I programmatically exit insert mode from an autocommand or Vimscript function?
:stopinsert
:stopinsert is an Ex command that immediately exits insert (or replace) mode and returns to normal mode.
command-line #insert-mode #ex-commands #autocommands #normal-mode
How do I run a shell command from Vimscript and capture its output as a list of individual lines?
systemlist()
systemlist({cmd}) runs a shell command and returns the output as a list of strings, one per line — unlike system() which returns everything as a single string
How do I manually fire an autocommand event to re-trigger filetype settings or test autocmds?
:doautocmd
:doautocmd fires any autocommand event manually, exactly as if that event had occurred naturally.
How do I insert a literal control character or special key into the command line?
<C-v> (command-line mode)
In command-line mode (after : or /), pressing followed by any key inserts that key literally — bypassing all key notation, mappings, and special interpretatio
How do I add custom markers or icons in Vim's sign column next to specific lines without any plugins?
:sign define and :sign place
Vim's built-in sign system lets you define custom symbols and place them in the sign column — the narrow gutter to the left of line numbers.
How do I pipe the contents of my current buffer as input to a shell command in Vim?
:w !cmd
The :w !cmd command sends the buffer's contents as standard input to an external command without modifying the buffer.
How do I open the command-line window mid-command to edit it with full Vim capabilities?
<C-f> (in command-line mode)
When you're already on the Vim command line and realize you need complex edits — inserting text from multiple positions, reordering arguments, or referencing
How do I evaluate a Vimscript expression and insert the result into a command-line command?
<C-r>= (command-line mode)
Just like = lets you insert evaluated expressions in insert mode, you can use it inside an Ex command on the command line to embed any Vimscript expression resu
How do I quickly evaluate and print a Lua expression in Neovim without calling print()?
:lua =expr
In Neovim, prefixing a Lua expression with = on the :lua command line evaluates it and pretty-prints the result using vim.
How do I delete all blank and whitespace-only lines from a file in Vim?
:g/^\s*$/d
The global command :g/^\s$/d removes every line that is empty or contains only whitespace — a common cleanup task when tidying up code, configuration files, o
How do I change the filetype of the current buffer to get correct syntax highlighting and indent rules?
:setfiletype {filetype}
:setfiletype {filetype} sets the filetype option for the current buffer only if it has not already been set.
How do I reference just the extension, stem, or directory of the current file in a Vim command?
%:e
Vim exposes the current filename as % in Ex commands, and you can apply modifiers to extract specific parts of the path.
How do I temporarily disable all autocommands when running an Ex command?
:noautocmd {command}
The :noautocmd prefix (abbreviated :noa) suppresses all autocommand events for the duration of the following command.
command-line #ex-commands #autocommands #performance #command-line #scripting
How do I delete the line immediately following every line that matches a pattern?
:g/pattern/+1d
Using :g/pattern/+1d you can delete the line that comes right after each line matching a pattern, in one pass.
How do I quickly create an Ex command range spanning the next N lines using a count before the colon?
5:
Typing a count before : in normal mode automatically fills in a line range in the command line.
command-line #command-line #ex-commands #ranges #normal-mode
How do I extract just the parent directory name (not the full path) of the current file in Vim?
expand('%:p:h:t')
Vim's filename modifiers can be chained to transform paths step by step.
How do I open the command-line window while in the middle of typing a command?
<C-f>
While typing in Vim's command line (after pressing :), pressing opens the command-line window with your current, unfinished command already filled in.
How do I switch from the active command line into the command-line window to edit the command with full Vim power?
<C-f> (in command line)
Pressing while you are already typing in the Vim command line (:), search line (/ or ?), or input prompt switches you into the command-line window with the curr
command-line #command-line #ex-commands #editing #normal-mode
How do I manually save the undo history for a file to a separate undo file in Vim?
:wundo {file}
The :wundo {file} command writes the current buffer's entire undo history to a file on disk.