为什么是Lua+；Nginx说它不能调用全局函数？

我有两个简单的函数，可以基于用户代理检测浏览器和操作系统，它们存储在文件

useragent.lua

中

function detect_browser_platform(user_agent)
    -- Here goes some string matching and similar stuff
    return browser_platform
end

function detect_os_platform(user_agent)
    -- Here goes some string matching and similar stuff
    return os_platform
end

function detect_env_pattern(user_agent)
    return detect_operating_system_platform(user_agent) .. "-" .. detect_browser_platform(user_agent) .. "-" .. ngx.var.geoip2_data_country_code
end

在虚拟主机配置文件中，有一行代码表示当请求看起来像执行lua脚本时：

/var/www/default/test.lua

在

test.lua

中，我有以下代码：

local posix = require('posix')
local redis = require('redis')
require('useragent')

-- Some code goes here

local user_agent = ngx.req.get_headers()['User-Agent']
local pattern_string = detect_env_pattern(user_agent)

ngx.say(pattern_string)
ngx.exit(200)

但是由于某种原因，当我重新加载nginx

nginx-s reload

时，这些代码只在第一次工作。当我发出另一个请求时，它会显示以下错误：

2016/09/19 12:30:08 [error] 19201#0: *125956 lua entry thread aborted: runtime error: /var/www/default/test.lua:199: attempt to call global 'detect_env_pattern' (a nil value)

我不知道这里发生了什么。我刚开始用Lua编程，没有时间深入理解语言。。。那么我为什么会出现这个错误呢？

用表格将其包装起来：

local M={};



function detect_browser_platform(user_agent)
    -- Here goes some string matching and similar stuff
    return browser_platform
end

function detect_os_platform(user_agent)
    -- Here goes some string matching and similar stuff
    return os_platform
end

function detect_env_pattern(user_agent)
    return detect_operating_system_platform(user_agent) .. "-" .. detect_browser_platform(user_agent) .. "-" .. ngx.var.geoip2_data_country_code
end

M.detect_env_pattern = detect_env_pattern
return M

在base

lua

文件中：

  local useragent = require('useragent')
    --.....
    local user_agent = ngx.req.get_headers()['User-Agent']
local pattern_string = useragent.detect_env_pattern(user_agent)

ngx.say(pattern_string)
ngx.exit(200)

用一张桌子把它包起来：

local M={};



function detect_browser_platform(user_agent)
    -- Here goes some string matching and similar stuff
    return browser_platform
end

function detect_os_platform(user_agent)
    -- Here goes some string matching and similar stuff
    return os_platform
end

function detect_env_pattern(user_agent)
    return detect_operating_system_platform(user_agent) .. "-" .. detect_browser_platform(user_agent) .. "-" .. ngx.var.geoip2_data_country_code
end

M.detect_env_pattern = detect_env_pattern
return M

在base

lua

文件中：

  local useragent = require('useragent')
    --.....
    local user_agent = ngx.req.get_headers()['User-Agent']
local pattern_string = useragent.detect_env_pattern(user_agent)

ngx.say(pattern_string)
ngx.exit(200)