init.lua

--[[
INDEX
	VIS CRAP
	ALIASES
	MODULE
	ENV
	IMPORT
	MAIN
	EXPORT
	RETURN

Synopsis
	Displays output of command on new window

Notes
	vis:message is a pad that persists between quits, it does not clear

Use
	require(module).Setup() or require(module)()

Bugs
	popen/cmd does not capture stderr, it displays to screen
--]]

---------------------------------------- VIS

local vis = _G.vis

---------------------------------------- ALIASES

local Concat = table.concat
local Popen = io.popen
local Gsub = string.gsub

---------------------------------------- MODULE

local M = {}

---------------------------------------- ENV

local env, mt = {}, {
	__index = _G

	, __newindex = function ()
		error("Error: Runaway assignment on vis-command module", 2)
	end
}
local _ENV = setmetatable(env, mt)

---------------------------------------- IMPORT

-- concatenates table of strings into a bourne shell args
-- If your shell is different this fails
local BourneShellArgs = function (args_as_sequence_of_strings_T)
	local R = args_as_sequence_of_strings_T or {}
	for i,v in ipairs(R) do
		R[i] = Gsub(v, "'", "'\\''")
	end
	return "'" .. Concat(R, "' '") .. "'"
end

---------------------------------------- MAIN

local function Command(argv, force)
	local command = BourneShellArgs(argv)
	local H = Popen(command) -- BUG: popen does not capture stderr
	-- it just spits it out immediately
	local output = H:read"a"
	local status, msg, code = H:close()
	if not status then
		vis:info( ('ERROR[%d]: "%s"'):format(code, msg) )
	end
	if output and output:find"%S" then
		vis:message(output)
	end
end

local function PipeCommand(argv, force, win, selection, range)
	local command = BourneShellArgs(argv)
	local exitN, stdout, stderr = vis:pipe(win.file, range, command)
	if exitN==0 then
		if stdout and stdout~="" then vis:message(stdout) end
		return true
	end

	local msg = {}
	if stdout and #stdout>0 then
		table.insert(msg, "STDOUT:")
		table.insert(msg, stdout)
	end
	if stderr and #stderr>0 then
		table.insert(msg, "STDERR:")
		table.insert(msg, stderr)
	end
	table.insert(msg, M.DIVIDER)

	vis:info( ("Exit status: %d"):format(exitN) )
	if #msg>0 then vis:message( table.concat(msg, "\n\n") )end
	return true
end

---------------------------------------- EXPORT

function M.Setup()
	vis:command_register('cmd', Command
		,'Launches <cmd> and pipes output into a new window'
	)
	vis:command_register('pipe', PipeCommand
		,'Pipes range|selection to <cmd> and return output'
	)
end

M.Command = Command
M.PipeCommand = PipeCommand
M.DIVIDER = "------------------------------"
mt.__CALL = M.Setup

---------------------------------------- RETURN

return M