fix invalid msg crashing socket

sys/apps/package.lua

@@ -0,0 +1,97 @@
+_G.requireInjector(_ENV)
+
+local Git      = require('git')
+local Packages = require('packages')
+local Util     = require('util')
+
+local fs       = _G.fs
+local term     = _G.term
+
+local args     = { ... }
+local action   = table.remove(args, 1)
+
+local function Syntax(msg)
+	_G.printError(msg)
+	print('\nSyntax: Package list | install [name] ... |  update [name] | uninstall [name]')
+	error(0)
+end
+
+local function progress(max)
+	-- modified from: https://pastebin.com/W5ZkVYSi (apemanzilla)
+	local _, y = term.getCursorPos()
+	local wide, _ = term.getSize()
+	term.setCursorPos(1, y)
+	term.write("[")
+	term.setCursorPos(wide - 6, y)
+	term.write("]")
+	local done = 0
+	return function()
+		done = done + 1
+		local value = done / max
+		term.setCursorPos(2,y)
+		term.write(("="):rep(math.floor(value * (wide - 8))))
+		local percent = math.floor(value * 100) .. "%"
+		term.setCursorPos(wide - percent:len(),y)
+		term.write(percent)
+	end
+end
+
+local function install(name)
+	local manifest = Packages:getManifest(name) or error('Invalid package')
+	local packageDir = fs.combine('packages', name)
+	local method = args[2] or 'local'
+	if method == 'remote' then
+		Util.writeTable(packageDir .. '/.install', {
+			mount = string.format('%s gitfs %s', packageDir, manifest.repository),
+		})
+		Util.writeTable(fs.combine(packageDir, '.package'), manifest)
+	else
+		local list = Git.list(manifest.repository)
+		local showProgress = progress(Util.size(list))
+		for path, entry in pairs(list) do
+			Util.download(entry.url, fs.combine(packageDir, path))
+			showProgress()
+		end
+	end
+	return
+end
+
+if action == 'list' then
+	for k in pairs(Packages:list()) do
+		Util.print('[%s] %s', Packages:isInstalled(k) and 'x' or ' ', k)
+	end
+	return
+end
+
+if action == 'install' then
+	local name = args[1] or Syntax('Invalid package')
+	if Packages:isInstalled(name) then
+		error('Package is already installed')
+	end
+	install(name)
+	print('installation complete')
+	return
+end
+
+if action == 'update' then
+	local name = args[1] or Syntax('Invalid package')
+	if not Packages:isInstalled(name) then
+		error('Package is not installed')
+	end
+	install(name)
+	print('update complete')
+	return
+end
+
+if action == 'uninstall' then
+	local name = args[1] or Syntax('Invalid package')
+	if not Packages:isInstalled(name) then
+		error('Package is not installed')
+	end
+	local packageDir = fs.combine('packages', name)
+	fs.delete(packageDir)
+	print('removed: ' .. packageDir)
+	return
+end
+
+Syntax('Invalid command')