= Buffers

== Commands

To open buffers or navigate through the buffers list see
<<commands#files-and-buffers,`:doc commands files-and-buffers`>>.

== Scratch Buffers

Scratch buffers are useful for volatile data and quick prototyping.
They are not linked to files, so Kakoune does not warn about unsaved
changes at exit, and the `:write` command requires an explicit filename.

One particular scratch buffer, named *\*scratch*\*, is automatically
created when there are no other buffers left in the current
session. (which is also the case at Kakoune's startup when no files to
open have been provided)

A scratch buffer can be created by passing the `-scratch` switch to the
`:edit` command.

== Debug Buffers

Debug buffers are used to gather diagnostics. They have a number of
restrictions compared to regular buffers:

- They are skipped when cycling over the buffers list.
- Their content is not considered for word completions with `word=all`
  completers
- Hooks are not always run (like the `BufCreate`/`BufClose` hooks)
- Display profiling is disabled

A specific *\*debug*\* buffer is used by Kakoune to write errors or
warnings.  This is also where the ouput of the `:debug` and the `:echo
-debug` commands will land.

A debug buffer can be created by passing the `-debug` switch to the
`:edit` command.

== FIFO Buffers

The `:edit` command can take a `-fifo` switch:

---------------------------------------------
:edit -fifo <filename> [-scroll] <buffername>
---------------------------------------------

In this case, a buffer named `<buffername>` is created which reads
its content from the fifo (also called "named pipe") `<filename>`.
When the fifo is written to, the buffer is automatically updated.

If the `-scroll` switch is specified, the window displaying the buffer
will scroll so that the newest data is always visible.

This is very useful for running some commands asynchronously while
displaying their result in a buffer. See `rc/make.kak` and `rc/grep.kak`
for examples.

When the write end of the fifo is closed, the buffer becomes an ordinary
<<buffers#scratch-buffers,scratch buffer>>. When the buffer is deleted,
Kakoune closes the read end of the fifo, so any program writing to it
will receive `SIGPIPE`. This is useful as it permits stopping the writing
program when the buffer is deleted.