awesome/lib/awful/spawn.lua

216 lines
7.6 KiB
Lua

---------------------------------------------------------------------------
--- Spawning of programs.
--
-- This module provides methods to start programs and supports startup
-- notifications, which allows for callbacks and applying properties to the
-- program after it has been launched. This requires currently that the
-- applicaton supports them.
--
-- @author Julien Danjou <julien@danjou.info>
-- @author Emmanuel Lepage Vallee <elv1313@gmail.com>
-- @copyright 2008 Julien Danjou
-- @copyright 2014 Emmanuel Lepage Vallee
-- @release @AWESOME_VERSION@
-- @module awful.spawn
---------------------------------------------------------------------------
local capi =
{
awesome = awesome,
mouse = mouse,
client = client,
}
local lgi = require("lgi")
local Gio = lgi.Gio
local GLib = lgi.GLib
local util = require("awful.util")
local spawn = {}
spawn.snid_buffer = {}
function spawn.on_snid_callback(c)
local props = spawn.snid_buffer[c.startup_id]
if props then
c:emit_signal("spawn::completed_with_payload", props)
spawn.snid_buffer[c.startup_id] = nil
end
end
function spawn.on_snid_cancel(id)
if spawn.snid_buffer[id] then
spawn.snid_buffer[id] = nil
end
end
--- Spawn a program, and optionally apply properties and/or run a callback.
--
-- Applying properties or running a callback requires the program/client to
-- support startup notifications.
--
-- See `awful.rules.execute` for more details about the format of `sn_rules`.
--
-- @tparam string|table cmd The command.
-- @tparam[opt=true] table|boolean sn_rules A table of properties to be applied
-- after startup; `false` to disable startup notifications.
-- @tparam[opt] function callback A callback function to be run after startup.
-- @treturn[1] integer The forked PID.
-- @treturn[1] ?string The startup notification ID, if `sn` is not false, or
-- a `callback` is provided.
-- @treturn[2] string Error message.
function spawn.spawn(cmd, sn_rules, callback)
if cmd and cmd ~= "" then
local enable_sn = (sn_rules ~= false or callback)
enable_sn = not not enable_sn -- Force into a boolean.
if not sn_rules and callback then
sn_rules = {callback=callback}
elseif callback then
sn_rules.callback = callback
end
local pid, snid = capi.awesome.spawn(cmd, enable_sn)
-- The snid will be nil in case of failure
if snid and type(sn_rules) == "table" then
spawn.snid_buffer[snid] = sn_rules
end
return pid, snid
end
-- For consistency
return "Error: No command to execute"
end
--- Spawn a program using the shell.
-- This calls `cmd` with `$SHELL -c` (via `awful.util.shell`).
-- @tparam string cmd The command.
function spawn.with_shell(cmd)
if cmd and cmd ~= "" then
cmd = { util.shell, "-c", cmd }
return capi.awesome.spawn(cmd, false)
end
end
--- Spawn a program and asynchronously and capture its output line by line.
-- @tparam string|table cmd The command.
-- @tab callbacks Table containing callbacks that should be
-- invoked on various conditions.
-- @tparam[opt] function callbacks.stdout Function that is called with each line of
-- output on stdout, e.g. `stdout(line)`.
-- @tparam[opt] function callbacks.stderr Function that is called with each line of
-- output on stderr, e.g. `stderr(line)`.
-- @tparam[opt] function callbacks.output_done Function to call when no more output
-- is produced.
-- @tparam[opt] function callbacks.exit Function to call when the spawned process
-- exits. This function gets the exit reason and code as its argument. The
-- reason can be "exit" or "signal". For "exit", the second argument is the exit
-- code. For "signal", the second argument is the signal causing process
-- termination.
-- @treturn[1] Integer the PID of the forked process.
-- @treturn[2] string Error message.
function spawn.with_line_callback(cmd, callbacks)
local stdout_callback, stderr_callback, done_callback, exit_callback =
callbacks.stdout, callbacks.stderr, callbacks.output_done, callbacks.exit
local have_stdout, have_stderr = stdout_callback ~= nil, stderr_callback ~= nil
local pid, sn_id, stdin, stdout, stderr = capi.awesome.spawn(cmd,
false, false, have_stdout, have_stderr, exit_callback)
if type(pid) == "string" then
-- Error
return pid
end
local done_before = false
local function step_done()
if have_stdout and have_stderr and not done_before then
done_before = true
return
end
done_callback()
end
if have_stdout then
spawn.read_lines(Gio.UnixInputStream.new(stdout, true),
stdout_callback, step_done, true)
end
if have_stderr then
spawn.read_lines(Gio.UnixInputStream.new(stderr, true),
stderr_callback, step_done, true)
end
assert(stdin == nil)
return pid
end
--- Read lines from a Gio input stream
-- @tparam Gio.InputStream input_stream The input stream to read from.
-- @tparam function line_callback Function that is called with each line
-- read, e.g. `line_callback(line_from_stream)`.
-- @tparam[opt] function done_callback Function that is called when the
-- operation finishes (e.g. due to end of file).
-- @tparam[opt=false] boolean close Should the stream be closed after end-of-file?
function spawn.read_lines(input_stream, line_callback, done_callback, close)
local stream = Gio.DataInputStream.new(input_stream)
local function done()
if close then
stream:close()
end
if done_callback then
xpcall(done_callback, function(err)
print(debug.traceback("Error while calling done_callback:"
.. tostring(err), 2))
end)
end
end
local start_read, finish_read
start_read = function()
stream:read_line_async(GLib.PRIORITY_DEFAULT, nil, finish_read)
end
finish_read = function(obj, res)
local line, length = obj:read_line_finish(res)
if type(length) ~= "number" then
-- Error
print("Error in awful.spawn.read_lines:", tostring(length))
done()
elseif #line ~= length then
-- End of file
done()
else
-- Read a line
xpcall(function()
-- This needs tostring() for older lgi versions which returned
-- "GLib.Bytes" instead of Lua strings (I guess)
line_callback(tostring(line))
end, function(err)
print(debug.traceback("Error while calling line_callback: "
.. tostring(err), 2))
end)
-- Read the next line
start_read()
end
end
start_read()
end
--- Read a program output and return its output as a string.
-- @tparam string cmd The command to run.
-- @treturn string A string with the program output, or the error if one
-- occured.
function spawn.pread(cmd)
if cmd and cmd ~= "" then
local f, err = io.popen(cmd, 'r')
if f then
local s = f:read("*all")
f:close()
return s
else
return err
end
end
end
capi.awesome.connect_signal("spawn::canceled" , spawn.on_snid_cancel )
capi.awesome.connect_signal("spawn::timeout" , spawn.on_snid_cancel )
capi.client.connect_signal ("manage" , spawn.on_snid_callback )
capi.client.add_signal ("spawn::completed_with_payload" )
return setmetatable(spawn, { __call = function(_, ...) return spawn.spawn(...) end })
-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80