run lua commands from shell and other tweaks

common/autorun/common.lua

@@ -6,3 +6,49 @@ end
 
 _ENV.shell.setCompletionFunction("packages/common/edit.lua", c)
 _ENV.shell.setCompletionFunction("packages/common/hexedit.lua", c)
+
+_ENV.shell.registerHandler(function(env, command, args)
+	if command:match('^!') then
+		return {
+			title = 'lua',
+			path = table.concat({ command:match('^!(.+)'), table.unpack(args) }, ' '),
+			args = args,
+			load = function(s)
+				return function()
+					local fn, m
+					local wrapped
+
+					fn = load('return (' ..s.. ')', 'lua', nil, env)
+
+					if fn then
+						fn = load('return {' ..s.. '}', 'lua', nil, env)
+						wrapped = true
+					end
+
+					if fn then
+						fn, m = pcall(fn)
+						if #m <= 1 and wrapped then
+							m = m[1]
+						end
+					else
+						fn, m = load(s, 'lua', nil, env)
+						if fn then
+							fn, m = pcall(fn)
+						end
+					end
+
+					if fn then
+						if m or wrapped then
+							require('opus.util').print(m or 'nil')
+						else
+							print()
+						end
+					else
+						_G.printError(m)
+					end
+				end
+			end,
+			env = env,
+		}
+	end
+end)