How do I pipe the entire buffer through an external shell command like sort, jq, or a formatter?

Explanation

:%!{command} replaces the entire buffer contents with the output of piping them through a shell command. This makes Vim a direct interface to Unix text-processing tools — sort, format, transform — without leaving the editor.

How it works

• % is a range meaning "all lines in the buffer"
• ! signals that what follows is a shell command
• The buffer's content is sent to the command's stdin, and stdout replaces the buffer

You can also filter a visual selection or a line range instead of the whole file:

:'<,'>!sort       " sort only the selected lines
:5,10!column -t  " align columns on lines 5-10

Example

Format a messy JSON buffer:

:%!python3 -m json.tool

Before:

{"name":"alice","age":30,"city":"NYC"}

After:

{
    "name": "alice",
    "age": 30,
    "city": "NYC"
}

Tips

• :%!sort -u sorts and removes duplicates in one step
• :.!date replaces the current line with the output of date
• :%!cat -n adds line numbers to the buffer
• If the command fails or produces no output, Vim warns you and you can undo with u
• In normal mode, !{motion}{cmd} also filters the range covered by the motion