Utils

ya

hide()

Hide Yazi to the secondary screen by returning to the terminal, completely controlled by the requested plugin.

local permit = ya.hide()

This method returns a permit for this resource. When it's necessary to restore the TUI display, call its drop() method:

permit:drop()

Note that since there's always only one available terminal control resource, ya.hide() cannot be called again before the previous permit is dropped, otherwise an error will be thrown, effectively avoiding deadlocks.

In/Out	Type
Return	Permit
Available	Async context only

file_cache(opts)

Calculate the cached Url corresponding to the given file.

ya.file_cache {
	-- File to be cached.
	file = file,
	-- Number of units to skip. It's units largely depend on your previewer,
	-- such as lines for code, and percentages for videos.
	skip = 1,
}

If the file is not allowed to be cached, such as it's ignored in the user config, or the file itself is a cache, returns nil.

In/Out	Type
opts	{ file: File, skip: integer }
Return	Url?

render()

Re-render the UI:

local update_state = ya.sync(function(self, new_state)
	self.state = new_state
	ya.render()
end)

In/Out	Type
Return	undefined
Available	Sync context only

mgr_emit(cmd, args)

Send a command to the [manager] without waiting for the executor to execute:

ya.mgr_emit("my-cmd", { "hello", 123, foo = true, bar_baz = "world" })

-- Equivalent to:
-- my-cmd "hello" "123" --foo --bar-baz="world"

In/Out	Type	Note
cmd	string	-
args	{ [integer|string]: Sendable }	Table values are Sendable that follow Ownership transfer rules
Return	undefined	-

image_show(url, rect)

Display the image of url within the rect, and the image will downscale to fit the area automatically:

In/Out	Type
url	Url
rect	Rect
Return	undefined
Available	Async context only

image_precache(src, dist)

Pre-cache the image of src as dist based on user-configured max_width and max_height.

In/Out	Type
src	Url
dist	Url
Return	undefined
Available	Async context only

which(opts)

Prompt users with a set of available keys:

local cand = ya.which {
	-- Key candidates, contains the following fields:
	--   `on`: Key to be prompted, which is a string or a table of strings if multiple.
	--   `desc`: Description of the key.
	cands = {
		{ on = "a" },
		{ on = "b", desc = "optional description" },
		{ on = "<C-c>", desc = "key combination" },
		{ on = { "d", "e" }, desc = "multiple keys" },
	},
	-- Whether to show the UI of key indicator
	silent = false,
}

When the user clicks a valid candidate, ya.which returns the 1-based index of that cand; otherwise, it returns nil, indicating that the user has canceled the key operation.

In/Out	Type
opts	{ cands: { on: string|string[], desc: string? }[], silent: boolean? }
Return	number?
Available	Async context only

input(opts)

Request user input:

local value, event = ya.input {
	-- Title
	title = "Archive name:",
	-- Default value
	value = "",
	-- Position, which is a table:
	-- 	`1`: Origin position, available values: "top-left", "top-center", "top-right",
	-- 	     "bottom-left", "bottom-center", "bottom-right", "center", and "hovered".
	-- 	`x`: X offset from the origin position.
	-- 	`y`: Y offset from the origin position.
	-- 	`w`: Width of the input.
	-- 	`h`: Height of the input.
	position = { "top-center", y = 3, w = 40 },
	-- Whether to report user input in real time.
	realtime = false,
	-- Number of seconds to wait for the user to stop typing, available if `realtime = true`.
	debounce = 0.3,
}

Returns (value, event):

• value: The user input value carried by this event, which is a string if the event is non-zero; otherwise, nil.
• event: The event type, which is an integer:
  • 0: Unknown error.
  • 1: The user has confirmed the input.
  • 2: The user has canceled the input.
  • 3: The user has changed the input (only if realtime is true).

When realtime = true specified, ya.input() returns a receiver, which has a recv() method that can be called multiple times to receive events:

local input = ya.input {
	title = "Input in realtime:",
	position = { "center", w = 50 },
	realtime = true,
}

while true do
	local value, event = input:recv()
	if not value then
		break
	end

	ya.dbg(value)
end

In/Out	Type
opts	{ title: string, value: string?, position: Pos, realtime: boolean?, debounce: number? }
Return	(string?, integer) | Recv
Available	Async context only

notify(opts)

Send a foreground notification to the user:

ya.notify {
	-- Title.
	title = "Hello, World!",
	-- Content.
	content = "This is a notification from Lua!",
	-- Timeout.
	timeout = 6.5,
	-- Level, available values: "info", "warn", and "error", default is "info".
	level = "info",
}

In/Out	Type
opts	{ title: string, content: string, timeout: number?, level: string? }
Return	undefined

dbg(msg, ...)

Append messages to the log file at the debug level:

ya.dbg("Hello", "World!")                       -- Multiple arguments are supported
ya.dbg({ foo = "bar", baz = 123, qux = true })  -- Any type of data is supported

In/Out	Type
msg	any
...	any
Return	undefined

err(msg, ...)

Append messages to the log file at the error level:

ya.err("Hello", "World!")                       -- Multiple arguments are supported
ya.err({ foo = "bar", baz = 123, qux = true })  -- Any type of data is supported

In/Out	Type
msg	any
...	any
Return	undefined

preview_code(opts)

Preview the file as code into the specified area:

ya.preview_code {
	-- Available preview area
  area = area,
	-- File to be previewed.
  file = file,
	-- Mimetype of the file.
  mime = "text/plain",
	-- Number of units to skip. The units depend on your previewer,
	-- such as lines for code and percentages for videos.
  skip = 1,
}

Returns (err, upper_bound):

• err: Error string if the preview fails; otherwise, nil.
• upper_bound: If the preview fails and it's because exceeds the maximum upper bound, return this bound; otherwise, nil.

In/Out	Type
opts	{ area: Rect, file: File, mime: string, skip: integer }
Return	(Error?, integer?)
Available	Async context only

preview_widgets(opts, widgets)

ya.preview_widgets({
	-- Available preview area.
  area = area,
	-- File to be previewed.
  file = file,
	-- Mimetype of the file.
  mime = "text/plain",
	-- Number of units to skip. The units depend on your previewer,
	-- such as lines for code and percentages for videos.
  skip = 1,
}, {
	ui.Text("Hello, World!"):area(area),
})

In/Out	Type
opts	{ area: Rect, file: File, mime: string, skip: integer }
widgets	Renderable[]
Return	undefined
Available	Async context only

sync(fn)

See Async context.

In/Out	Type
fn	fun(...: any): any
Return	fun(...: any): any

target_os()

Returns a string describing the specific operating system in use.

In/Out	Type
Return	string | "linux" | "macos" | "ios" | "freebsd" | "dragonfly" | "netbsd" | "openbsd" | "solaris" | "android" | "windows"

target_family()

Returns the family of the operating system.

In/Out	Type
Return	string | "unix" | "windows" | "wasm"

hash(str)

Returns the hash of str:

ya.hash("Hello, World!")

It is designed to work with algorithm-independent tasks, such as generating file cache names.

The current implementation uses MD5, but it will be replaced with a faster hash algorithm, like xxHash, in the future. So, don't rely on this implementation detail.

In/Out	Type
str	string
Return	string
Available	Async context only

quote(str)

Quote characters in str that may have special meaning in a shell:

local handle = io.popen("ls " .. ya.quote(filename))

In/Out	Type
str	string
Return	string

truncate(text, opts)

Truncate the text to the specified width and return the truncated result:

ya.truncate("Hello, World!", {
	-- Maximum width of the text.
	max = 5,
	-- Whether to truncate the text from right-to-left.
	rtl = false
})

In/Out	Type
text	string
opts	{ max: integer, rtl: boolean? }
Return	string

clipboard(text)

Get or set the content of the system clipboard:

-- Get contents from the clipboard if no argument is provided
local content = ya.clipboard()

-- Set contents to the clipboard
ya.clipboard("new content")

In/Out	Type
text	string?
Return	string?
Available	Async context only

time()

Returns the current timestamp, which is a float, the integer part represents the seconds, and the decimal part represents the milliseconds.

In/Out	Type
Return	number

sleep(secs)

Waits until secs has elapsed:

ya.sleep(0.5)  -- Sleep for 500 milliseconds

In/Out	Type
secs	number
Return	undefined
Available	Async context only

uid()

Returns the id of the current user.

In/Out	Type
Return	integer
Available	Unix-like systems only

gid()

Returns the group id of the current user.

In/Out	Type
Return	integer
Available	Unix-like systems only

user_name(uid)

Get the username by uid:

-- Get the current user's name if no argument is provided
ya.user_name()

-- Get the name of user with id 1000
ya.user_name(1000)

In/Out	Type
uid	integer?
Return	string?
Available	Unix-like systems only

group_name(gid)

Get the group name by gid:

-- Get the current user's group name if no argument is provided
ya.group_name()

-- Get the name of group with id 1000
ya.group_name(1000)

In/Out	Type
gid	integer?
Return	string?
Available	Unix-like systems only

host_name()

Returns the hostname of the current machine.

In/Out	Type
Return	string?
Available	Unix-like systems only

ps

Yazi's DDS (Data Distribution Service) uses a Lua-based publish-subscribe model as its carrier. That is, you can achieve cross-instance communication and state persistence through the ps API. See DDS for details.

The following functions can only be used within a sync context.

pub(kind, value)

Publish a message to the current instance, and all plugins subscribed through sub() for this kind will receive it, achieving internal communication within the instance:

ps.pub("greeting", "Hello, World!")

Since the kind is used globally, to add the plugin name as the prefix is a best practice. For example, the combination of the plugin my-plugin and the kind event1 would be my-plugin-event1.

In/Out	Type	Note
kind	string	Alphanumeric with dashes, cannot be built-in kinds
value	Sendable	A Sendable value that follows Ownership transfer rules
Return	undefined	-

pub_to(receiver, kind, value)

Publish a message to a specific instance with receiver as the ID:

ps.pub_to(1711957283332834, "greeting", "Hello, World!")

Where:

• Local - receiver is the current instance, and is subscribed to this kind via sub(), it will receive the message.
• Remote - receiver isn't the current instance, and is subscribed to this kind via sub_remote(), it will receive the message.
• Broadcast - receiver is 0, all remote instances subscribed to this kind via sub_remote() will receive the message.

In/Out	Type	Note
receiver	integer	-
kind	string	Alphanumeric with dashes, cannot be built-in kinds
value	Sendable	A Sendable value that follows Ownership transfer rules
Return	undefined	-

sub(kind, callback)

Subscribe to local messages of kind and call the callback handler for it:

-- The same `kind` from the same plugin can only be subscribed once,
-- re-subscribing (`sub()`) before unsubscribing (`unsub()`) will throw an error.
ps.sub("cd", function(body)
	ya.dbg("New cwd", cx.active.current.cwd)
end)

It runs in a sync context, so you can access app data via cx for the content of interest.

In/Out	Type	Note
kind	string	Alphanumeric with dashes, cannot be built-in kinds
callback	fun(body: Sendable)	No time-consuming work should be done in the callback
Return	undefined	-

sub_remote(kind, callback)

Same as sub(), except it subscribes to remote messages of this kind instead of local.

In/Out	Type	Note
kind	string	Same as sub()
callback	fun(body: Sendable)	Same as sub()
Return	undefined	-

unsub(kind)

Unsubscribe from local messages of this kind:

ps.unsub("my-message")

In/Out	Type	Note
kind	string	Alphanumeric with dashes, cannot be built-in kinds
Return	undefined	-

unsub_remote(kind)

Unsubscribe from remote messages of this kind:

ps.unsub_remote("my-message")

In/Out	Type	Note
kind	string	Same as unsub()
Return	undefined	-

fs

The following functions can only be used within an async context.

cwd()

Get the current working directory (CWD) of the process.

This API was added to compensate for the lack of a getcwd in Lua; it is used to retrieve the directory of the last chdir call:

local url, err = fs.cwd()

You probably will never need it, and more likely, you'll need cx.active.current.cwd, which is the current directory where the user is working.

Specifically, when the user changes the directory, cx.active.current.cwd gets updated immediately, while synchronizing this update with the filesystem via chdir involves I/O operations, such as checking if the directory is valid.

So, there may be some delay, which is particularly noticeable on slow devices. For example, when an HDD wakes up from sleep, it typically takes 3~4 seconds.

It is useful if you just need a valid directory as the CWD of a process to start some work that doesn't depend on the CWD.

In/Out	Type
Return	(Url?, Error?)
Available	Async context only

cha(url, follow)

Get the Cha of the specified url:

-- Not following symbolic links
local cha, err = fs.cha(url)

-- Follow symbolic links
local cha, err = fs.cha(url, true)

In/Out	Type
url	Url
follow	boolean?
Return	(Cha?, Error?)
Available	Async context only

write(url, data)

Write data to the specified url:

local ok, err = fs.write(url, "hello world")

In/Out	Type
url	Url
data	string
Return	(boolean, Error?)
Available	Async context only

create(type, url)

Create file(s) at the url of the file system:

local ok, err = fs.create("dir_all", Url("/tmp/test/nest/nested"))

Where type can be one of the following:

• "dir": Creates a new, empty directory.
• "dir_all": Recursively create a directory and all of its parents if they are missing.

In/Out	Type
type	string | "dir" | "dir_all"
url	Url
Return	(boolean, Error?)
Available	Async context only

remove(type, url)

Remove file(s) at the url of the file system:

local ok, err = fs.remove("file", Url("/tmp/test.txt"))

Where type can be one of the following:

• "file": Removes a file from the filesystem.
• "dir": Removes an existing, empty directory.
• "dir_all": Removes a directory at this url, after removing all its contents. Use carefully!
• "dir_clean": Remove all empty directories under it, and if the directory itself is empty afterward, remove it as well.

In/Out	Type
type	string | "file" | "dir" | "dir_all" | "dir_clean"
url	Url
Return	(boolean, Error?)
Available	Async context only

read_dir(url, options)

Reads the directory contents of url:

local files, err = fs.read_dir(url, {
	-- Glob pattern to filter files out if provided.
	glob = nil,
	-- Maximum number of files to read, defaults to unlimited.
	limit = 10,
	-- Whether to resolve symbolic links, defaults to `false`.
	resolve = false,
})

In/Out	Type
url	Url
options	{ glob: string?, limit: integer?, resolve: boolean? }
Return	(File[]?, Error?)
Available	Async context only

unique_name(url)

Get a unique name from the given url to ensure it's unique in the filesystem:

local url, err = fs.unique_name(Url("/tmp/test.txt"))

If the file already exists, it will append _n to the filename, where n is a number, and keep incrementing until the first available name is found.

In/Out	Type
url	Url
Return	(Url?, Error?)
Available	Async context only

Command

You can invoke external programs through:

local child, err = Command("ls")
	:args({ "-a", "-l" })
	:stdout(Command.PIPED)
	:spawn()

Compared to Lua's os.execute, it provides many comprehensive and convenient methods, and the entire process is async.

It takes better advantage of the benefits of concurrent scheduling. However, it can only be used in async contexts, such as preloaders, previewers, and async functional plugins.

arg(self, arg)

Append an argument to the command:

local cmd = Command("ls"):arg("-a"):arg("-l")

In/Out	Type
self	Command
arg	string
Return	self

args(args)

Append multiple arguments to the command:

local cmd = Command("ls"):args({ "-a", "-l" }):args({ "-h" })

In/Out	Type
self	Command
arg	string[]
Return	self

cwd(self, dir)

Set the current working directory of the command:

local cmd = Command("ls"):cwd("/root")

In/Out	Type
self	Command
dir	string
Return	self

env(self, key, value)

Append an environment variable to the command:

local cmd = Command("ls"):env("PATH", "/bin"):env("HOME", "/home")

In/Out	Type
self	Command
key	string
value	string
Return	self

stdin(self, stdio)

Set the stdin of the command:

local cmd = Command("ls"):stdin(Command.PIPED)

Where stdio can be one of the following:

• Command.PIPED: Pipe the stdin.
• Command.NULL: Discard the stdin (default).
• Command.INHERIT: Inherit the stdin.

In/Out	Type
self	Command
stdio	Stdio
Return	self

stdout(self, stdio)

Set the stdout of the command:

local cmd = Command("ls"):stdout(Command.PIPED)

Where stdio can be one of the following:

• Command.PIPED: Pipe the stdout.
• Command.NULL: Discard the stdout (default).
• Command.INHERIT: Inherit the stdout.

In/Out	Type
self	Command
stdio	Stdio
Return	self

stderr(self, stdio)

Set the stderr of the command:

local cmd = Command("ls"):stderr(Command.PIPED)

Where stdio can be one of the following:

• Command.PIPED: Pipe the stderr.
• Command.NULL: Discard the stderr (default).
• Command.INHERIT: Inherit the stderr.

In/Out	Type
self	Command
stdio	Stdio
Return	self

spawn(self)

Spawn the command:

local child, err = Command("ls"):spawn()

In/Out	Type
self	Command
Return	(Child?, Error?)

output(self)

Spawn the command and wait for it to finish:

local output, err = Command("ls"):output()

In/Out	Type
self	Command
Return	(Output?, Error?)

status(self)

Executes the command as a child process, waiting for it to finish and collecting its exit status:

local status, err = Command("ls"):status()

In/Out	Type
self	Command
Return	(Status?, Error?)

Child

This object is created by Command:spawn() and represents a running child process.

You can access the runtime data of this process through its proprietary methods.

read(self, len)

Reads data from the available data source alternately:

local data, event = child:read(1024)

"available data source" refers to stdout or stderr that has Command.PIPED set, or them both, the event indicates where the data comes from:

• Data comes from stdout, if event is 0.
• Data comes from stderr, if event is 1.
• No data to read from both stdout and stderr, if event is 2.

In/Out	Type
self	Child
len	integer
Return	(string, integer)

read_line(self)

Same as read(), except it reads data line by line:

local line, event = child:read_line()

In/Out	Type
self	Child
Return	(string, integer)

read_line_with(self, opts)

Same as read_line(), except it accepts a table of options:

local line, event = child:read_line_with {
	-- Timeout to read
	timeout = 500,
}

It has a extra event:

• Timeout, if event is 3.

In/Out	Type
self	Child
opts	{ timeout: integer }
Return	(string, integer)

write_all(self, src)

Writes all src to the stdin of the child process:

local ok, err = child:write_all(src)

Ensure that the child's stdin is available when calling this method, specifically:

1. stdin(Command.PIPED) is set.
2. take_stdin() has never been called.

Otherwise, an error will be thrown.

In/Out	Type
self	Child
src	string
Return	(boolean, Error?)

flush(self)

Flushes any buffered data to the stdin of the child process:

local ok, err = child:flush()

Ensure that the child's stdin is available when calling this method, specifically:

1. stdin(Command.PIPED) is set.
2. take_stdin() has never been called.

Otherwise, an error will be thrown.

In/Out	Type
self	Child
Return	(boolean, Error?)

wait(self)

Wait for the child process to finish:

local status, err = child:wait()

In/Out	Type
self	Child
Return	(Status?, Error?)

wait_with_output(self)

Wait for the child process to finish and get the output:

local output, err = child:wait_with_output()

In/Out	Type
self	Child
Return	(Output?, Error?)

start_kill(self)

Send a SIGTERM signal to the child process:

local ok, err = child:start_kill()

In/Out	Type
self	Child
Return	(boolean, Error?)

take_stdin(self)

Take and return the stdin stream of the child process:

local stdin = child:take_stdin()

This method can only be called once and is only applicable to processes with stdin(Command.PIPED) set; otherwise, it returns nil.

In/Out	Type
self	Child
Return	Stdio?

take_stdout(self)

Take and return the stdout stream of the child process:

local stderr = child:take_stdout()

which is useful when redirecting stdout to another process's stdin:

local echo = Command("echo"):arg("Hello"):stdout(Command.PIPED):spawn()

local rev = Command("rev"):stdin(echo:take_stdout()):stdout(Command.PIPED):output()

ya.dbg(rev.stdout) -- "olleH\n"

This method can only be called once and is only applicable to processes with stdout(Command.PIPED) set; otherwise, it returns nil.

In/Out	Type
self	Child
Return	Stdio?

take_stderr(self)

Take and return the stderr stream of the child process:

local stderr = child:take_stderr()

See take_stdout() for an example.

This method can only be called once and is only applicable to processes with stderr(Command.PIPED) set; otherwise, it returns nil.

In/Out	Type
self	Child
Return	Stdio?

Output

status

Status of the child process.

Type	Status

stdout

Stdout of the child process.

Type	string

stderr

Stderr of the child process.

Type	string

Status

This object represents the exit status of a child process, and it is created by wait(), or output().

success

Whether the child process exited successfully.

Type	boolean

code

Exit code of the child process.

Type	integer?