lua基础学习

参考酷壳大叔的博客，http://coolshell.cn/articles/10739.html， 自己搭建了一套nginx+lua的环境，学习了一下的case:

--nginx变量  
local var = ngx.var  
ngx.say("ngx.var.a : ", var.a)  
ngx.say("ngx.var.b : ", var.b)  

--[[
ngx.say("ngx.var[2] : ", var[2])  
ngx.var.b = 2;  

--请求头  
local headers = ngx.req.get_headers()  
ngx.say("headers begin")  
ngx.say("Host : ", headers["Host"])  
ngx.say("user-agent : ", headers["user-agent"])  
ngx.say("user-agent : ", headers.user_agent)  
for k,v in pairs(headers) do  
    if type(v) == "table" then  
        ngx.say(k, " : ", table.concat(v, ","))  
    else  
        ngx.say(k, " : ", v)  
    end  
end  
ngx.say("headers end")  
  
--get请求uri参数  
ngx.say("uri args begin")  
local uri_args = ngx.req.get_uri_args()  
for k, v in pairs(uri_args) do  
    if type(v) == "table" then  
        ngx.say(k, " : ", table.concat(v, ", "))  
    else  
        ngx.say(k, ": ", v)  
    end  
end  
ngx.say("uri args end")  
  
--post请求参数  
ngx.req.read_body()  
ngx.say("post args begin")  
local post_args = ngx.req.get_post_args()  
for k, v in pairs(post_args) do  
    if type(v) == "table" then  
        ngx.say(k, " : ", table.concat(v, ", "))  
    else  
        ngx.say(k, ": ", v)  
    end  
end  
ngx.say("post args end")  

--[[
ngx.say("ngx.req.http_version : ", ngx.req.http_version())   
ngx.say("ngx.req.get_method : ", ngx.req.get_method())  
--
ngx.say("ngx.req.raw_header : ",  ngx.req.raw_header())  
--
ngx.say("ngx.req.get_body_data() : ", ngx.req.get_body_data())  
--]]


--learn table
table1 = {[1]="2", [3]="3", ["name"] = "lishuming01"}

--ngx.say(table.concat(table1, " "))

for  k, v in pairs(table1) do
  ngx.say(k,"->",v)
end

--learn array
arr = {1,3,5,7,9}
for i=1, #arr do
    ngx.say(arr[i])
end

--learn metatable

f_op = {}
function f_op.__add(f1,f2)
    ret = {}
    ret.n = f1.n * f2.d + f1.d * f2.n
    ret.d = f1.d * f2.d
    return ret
end
f_op1 = {n=2, d=3}
f_op2 = {n=3, d=6}
setmetatable(f_op1, f_op)
setmetatable(f_op2, f_op)
ret = f_op1 + f_op2
for  k, v in pairs(ret) do
  ngx.say(k,"->",v)
end



--lean class
Person = {}

function Person:new( p )
    -- body
    local obj = p
    if (p == nil)then
        obj = {name="person", age=0}
    end
    self.__index = self
    return setmetatable(obj, self)
end

function Person:to_string()
    -- body
    return self.name .. ":" .. self.age
end

man1 = Person:new()
ngx.say(man1:to_string())


--todo: learn module