Luvref

INTRODUCTION luv luv-intro uv

local uv = vim.loop
local server = uv.new_tcp()
server:bind(“127.0.0.1”, 1337)
server:listen(128, function (err)
assert(not err, err)
local client = uv.new_tcp()
server:accept(client)
client:read_start(function (err, chunk)
assert(not err, err)
if chunk then
client:write(chunk)
else
client:shutdown()
client:close()
end
end)
end)
print(“TCP server listening at 127.0.0.1 port 1337”)
uv.run() — an explicit run call is necessary outside of luvit

CONTENTS luv-contents

ERROR HANDLING luv-error-handling

VERSION CHECKING luv-version-checking

uv_loop_t — Event loop luv-event-loop uv_loop_t

uv.loop_configure("block_signal", "sigprof")

-- Example usage of uv.walk to close all handles that
-- aren't already closing.
uv.walk(function (handle)
  if not handle:is_closing() then
    handle:close()
  end
end)

uv_req_t — Base request luv-base-request uv_req_t

uv_handle_t — Base handle luv-base-handle uv_handle_t

REFERENCE COUNTING luv-reference-counting

uv_timer_t — Timer handle luv-timer-handle uv_timer_t

-- Creating a simple setTimeout wrapper
local function setTimeout(timeout, callback)
  local timer = uv.new_timer()
  timer:start(timeout, 0, function ()
    timer:stop()
    timer:close()
    callback()
  end)
  return timer
end
— Creating a simple setInterval wrapper
local function setInterval(interval, callback)
local timer = uv.new_timer()
timer:start(interval, interval, function ()
callback()
end)
return timer
end
— And clearInterval
local function clearInterval(timer)
timer:stop()
timer:close()
end

uv_prepare_t — Prepare handle luv-prepare-handle uv_prepare_t

local prepare = uv.new_prepare()
prepare:start(function()
  print("Before I/O polling")
end)

uv_check_t — Check handle luv-check-handle uv_check_t

local check = uv.new_check()
check:start(function()
  print("After I/O polling")
end)

uv_idle_t — Idle handle luv-idle-handle uv_idle_t

local idle = uv.new_idle()
idle:start(function()
  print("Before I/O polling, no blocking")
end)

uv_async_t — Async handle luv-async-handle uv_async_t

local async
async = uv.new_async(function()
  print("async operation ran")
  async:close()
end)
async:send()

uv_poll_t — Poll handle luv-poll-handle uv_poll_t

uv_signal_t — Signal handle luv-signal-handle uv_signal_t

-- Create a new signal handler
local signal = uv.new_signal()
-- Define a handler function
uv.signal_start(signal, "sigint", function(signal)
  print("got " .. signal .. ", shutting down")
  os.exit(1)
end)

uv_process_t — Process handle luv-process-handle uv_process_t

local stdin = uv.new_pipe()
local stdout = uv.new_pipe()
local stderr = uv.new_pipe()
print(“stdin”, stdin)
print(“stdout”, stdout)
print(“stderr”, stderr)
local handle, pid = uv.spawn(“cat”, {
stdio = {stdin, stdout, stderr}
}, function(code, signal) — on exit
print(“exit code”, code)
print(“exit signal”, signal)
end)
print(“process opened”, handle, pid)
uv.read_start(stdout, function(err, data)
assert(not err, err)
if data then
print(“stdout chunk”, stdout, data)
else
print(“stdout end”, stdout)
end
end)
uv.read_start(stderr, function(err, data)
assert(not err, err)
if data then
print(“stderr chunk”, stderr, data)
else
print(“stderr end”, stderr)
end
end)
uv.write(stdin, “Hello World”)
uv.shutdown(stdin, function()
print(“stdin shutdown”, stdin)
uv.close(handle, function()
print(“process closed”, handle, pid)
end)
end)

uv_stream_t — Stream handle luv-stream-handle uv_stream_t

server:listen(128, function (err)
  local client = uv.new_tcp()
  server:accept(client)
end)

stream:read_start(function (err, chunk)
  if err then
    -- handle read error
  elseif chunk then
    -- handle data
  else
    -- handle disconnect
  end
end)

uv_tcp_t — TCP handle luv-tcp-handle uv_tcp_t

local client = uv.new_tcp()
client:connect("127.0.0.1", 8080, function (err)
  -- check error and carry on.
end)

-- Simple read/write with tcp
local fds = uv.socketpair(nil, nil, {nonblock=true}, {nonblock=true})
local sock1 = uv.new_tcp()
sock1:open(fds[1])
local sock2 = uv.new_tcp()
sock2:open(fds[2])
sock1:write(“hello”)
sock2:read_start(function(err, chunk)
assert(not err, err)
print(chunk)
end)

uv_pipe_t — Pipe handle luv-pipe-handle uv_pipe_t

local pipe = uv.new_pipe(false)
pipe:bind(‘/tmp/sock.test’)
pipe:listen(128, function()
local client = uv.new_pipe(false)
pipe:accept(client)
client:write(“hello!\n”)
client:close()
end)

-- Simple read/write with pipe_open
local fds = uv.pipe({nonblock=true}, {nonblock=true})
local read_pipe = uv.new_pipe()
read_pipe:open(fds.read)
local write_pipe = uv.new_pipe()
write_pipe:open(fds.write)
write_pipe:write(“hello”)
read_pipe:read_start(function(err, chunk)
assert(not err, err)
print(chunk)
end)

uv_tty_t — TTY handle luv-tty-handle uv_tty_t

-- Simple echo program
local stdin = uv.new_tty(0, true)
local stdout = uv.new_tty(1, false)
stdin:read_start(function (err, data)
assert(not err, err)
if data then
stdout:write(data)
else
stdin:close()
stdout:close()
end
end)

uv_udp_t — UDP handle luv-udp-handle uv_udp_t

uv_fs_event_t — FS Event handle luv-fs-event-handle uv_fs_event_t

uv_fs_poll_t — FS Poll handle luv-fs-poll-handle uv_fs_poll_t

FILE SYSTEM OPERATIONS luv-file-system-operations uv_fs_t

local function readFileSync(path)
  local fd = assert(uv.fs_open(path, "r", 438))
  local stat = assert(uv.fs_fstat(fd))
  local data = assert(uv.fs_read(fd, stat.size, 0))
  assert(uv.fs_close(fd))
  return data
end
local data = readFileSync(“main.lua”)
print(“synchronous read”, data)

local function readFile(path, callback)
  uv.fs_open(path, "r", 438, function(err, fd)
    assert(not err, err)
    uv.fs_fstat(fd, function(err, stat)
      assert(not err, err)
      uv.fs_read(fd, stat.size, 0, function(err, data)
        assert(not err, err)
        uv.fs_close(fd, function(err)
          assert(not err, err)
          return callback(data)
        end)
      end)
    end)
  end)
end
readFile(“main.lua”, function(data)
print(“asynchronous read”, data)
end)

THREAD POOL WORK SCHEDULING luv-thread-pool-work-scheduling

local function work_callback(a, b)
  return a + b
end
local function after_work_callback(c)
print(“The result is: ” .. c)
end
local work = uv.new_work(work_callback, after_work_callback)
work:queue(1, 2)
— output: “The result is: 3”

DNS UTILITY FUNCTIONS luv-dns-utility-functions

THREADING AND SYNCHRONIZATION UTILITIES luv-threading-and-synchronization-utilities

MISCELLANEOUS UTILITIES luv-miscellaneous-utilities

METRICS OPERATIONS luv-metrics-operations

CREDITS luv-credits