A simple Lua install script for Lua modules, extensions and scripts. Tested on Windows and Linux.

install.lua

#!/usr/bin/env lua

--[[  -- installing LDoc
function install()
--    requires('pl','Penlight')
--    install_script 'ldoc'
end
--]]

-- --[[
function install()
    requires ('lfs','luafilesystem')
    from 'lua'
    install_lua_package 'mod'
end
--]]

function install_lua_package (dir)
    copyd(join(dir),lua_lpath())
end

function install_ext_package (dir)
    copyd(join(dir),lua_cpath())
end

function install_lua (mod)
    local file = mod2file(mod)..'.lua'
    copyf(join(file),lpath)
end

function install_ext (mod)
    local file = mod2file(mod)..DEXT
    copyf(join(file),cpath)
end

function install_script (file)
    file = join(file)
    local bindir = check_bin_dir()
    local name = file
    if not exists(file) then
        file = exists(file..'.lua')
        if not file then quit("cannot find script") end
    end
    local pwd = cwd()
    local dest = bindir..DIRSEP..name..SEXT
    local f,e = io.open(dest,'w')
    if not f then quit("cannot create script "..e) end
    print('writing',dest)
    if WINDOWS then
        f:write '@echo off\n'
        f:write (LUA,' ',pwd,'\\',file,' %*\n')
    else
        f:write(LUA,' ',pwd,'/',file,' "$@"\n')
    end
    f:close()
    if not WINDOWS then
        run_command('chmod +x '..dest)
    end
end

function cwd ()
    return result_run_command(CWD)
end

function result_run_command(cmd)
    local f,e = io.popen(cmd..'  2>&1')
    if e then quit(e) end
    local res = f:read '*a':gsub('\n$','')
    f:close()
    return res
end

function mod2file (mod)
    return (mod:gsub('%.','/'))
end

function copyf(src, dest)
    if not exists(src) then quit("cannot find '"..src.."'") end
    local dir = src:match('.-[/\\](.-)[%w_]+%.%a+$')
    print ('dir',dir)
    if WINDOWS then
        run_command( 'xcopy /S /I /Y '..src..'  '..quote(dest..dir))
    else
        local target_dir = dest..dir
        mkdir(target_dir)
        run_command('cp -r  '..src..' '..target_dir)
    end
end

function copyd(src,dest)
    local dirname = src:match '[%w_]+$'
    if WINDOWS then
        run_command('xcopy /S /I /Y '..src..' '..quote(dest..dirname))
    else
        mkdir(dest)
        run_command('cp -r  '..src..' '..dest)
    end
end

function run_command(cmd,dont_fail)
    print(cmd)
    local res,x1,x2 = os.execute(cmd)
    -- Lua 5.1/5.2 compatible check
    local ff
    if res == nil or (type(res) == 'number' and res ~= 0) then
        if not dont_fail then
            quit 'command failed: were you running as an administrator?'
        end
    end
end

function exists(file)
    local f = io.open(file)
    if not f then  return nil
    else   f:close();   return file
    end
end

function err (msg)
    io.stderr:write('install: ',msg,'\n')
end

function quit(msg)
    err(msg)
    os.exit(1)
end

function requires(mod,name,nofail)
    local ok
    if type(mod) == 'table' then
        ok = true
        for i = 1,#mod,2 do
            ok = ok and requires(mod[i],mod[i+1],true)
        end
        if ok then return true end
    else
        ok = pcall(require,mod)
        if not ok then
            err('this package requires '..name)
        end
    end
    if not ok and not nofail then
        quit("unmet dependencies")
    end
    return ok
end

function check(mod)
    requires(mod,'failed')
end

local created = {}

function mkdir(dest)
    if not created[dest] then
        run_command('mkdir -p '..dest)
        created[dest] = true
    end
end

function quote (f)
    if WINDOWS and f:match '%s' then
        f = '"'..f..'"'
    end
    return f
end

function isabs (f)
    return f:match(ABSPAT)
end

function canonical (f)
    if not WINDOWS then return f end
    return f:gsub('/','\\'):lower()
end

local src_dir

function from (dir)
    src_dir = dir
end

function join (p)
    p = canonical(p)
    if not src_dir then return p end
    return src_dir..DIRSEP..p
end

DIRSEP = package.config:sub(1,1)
WINDOWS = DIRSEP  == '\\'
if not WINDOWS then
    DEXT = '.so'
    ABSPAT = '^/'
    SEXT = ''
    CWD = 'pwd'
else
    DEXT = '.dll'
    ABSPAT = '^%a:\\'
    SEXT = '.bat'
    CWD = 'cd'
end

local opath = os.getenv 'PATH'

-- find all directories in a list which are writeable by current user
function user_writeable(paths)
    local results, append = {}, table.insert
    local me = os.getenv 'USER'
    local f = io.popen('ls -ld '..paths..' 2>&1')
    for line in f:lines() do
        local type,id,user = line:match '(%S+)%s+(%S+)%s+(%S+)'
        if user == me then
            line = line:match '(%S+)$'
            append(results,line)
        end
    end
    f:close()
    return results
end

-- are we sudo?
if not WINDOWS then
    local f = io.popen 'id -u'
    local res = f:read()
    f:close()
    SUDO = res == '0'
end

local bindir

function which(prog)
    if not prog:match '%.exe$' then prog = prog..'.exe' end
    for dir in opath:gmatch '[^;]+' do
        local file = exists(dir..DIRSEP..prog)
        if file then return file end
    end
end

-- if we are God, then use /usr/local/bin; otherwise try to see if $HOME/bin
-- is on the path and actually exists.
-- For Windows, use the Lua binary directory for scripts.
function check_bin_dir()
    if bindir then return bindir end
    if WINDOWS then
        if not isabs(LUA) then
            LUA = which (LUA)
        end
        bindir = LUA:match '(.+)\\'
    else
        if SUDO then
            bindir = '/usr/local/bin'
        else -- let's go for a hunt
            bindir = os.getenv 'HOME'..'/bin'
            local paths = user_writeable(opath:gsub(':',' '))
            if not contains(paths,bindir) then
                quit("sorry cannot install binary without superuser permissions")
            end
        end
    end
    return bindir
end

function contains(ls,value)
    for _, v in ipairs(ls) do
        if v == value then return true end
    end
    return false
end

-- On Unix, the idea here is to find a Lua module path that is user writeable.

-- find absolute Lua module paths
function find_lua_path(package_path)
    local paths, append = {}, table.insert
    for p in package_path:gmatch('[^;]+') do
        if isabs(p) then
            -- get the path with trailiing slash and nothing afterwards
            append(paths, p:match ('[^?]+'))
        end
    end
    if not WINDOWS then
        paths = user_writeable(table.concat(paths,' '))
        if #paths == 0 then
            quit("sorry cannot install Lua module without superuser permissions")
        end
    end
    return paths[1]
end


local lpath,cpath

function lua_lpath()
    if lpath then return lpath end
    lpath = find_lua_path(package.path)
    return lpath
end

function lua_cpath()
    if cpath then return cpath end
    cpath = find_lua_path(package.cpath)
    return cpath
end

LUA = arg[-1]

install()