问题描述
|
我使用lua 5.1和luaSocket 2.0.2-4从Web服务器检索页面。我首先检查服务器是否响应,然后将Web服务器响应分配给lua变量。
local mysocket = require(\"socket.http\")
if mysocket.request(URL) == nil then
print(\'The server is unreachable on:\\n\'..URL)
return
end
local response,httpCode,header = mysocket.request(URL)
一切正常,但请求执行了两次。我想知道我是否可以做类似的事情(显然不起作用):
local mysocket = require(\"socket.http\")
if (local response,header = mysocket.request(URL)) == nil then
print(\'The server is unreachable on:\\n\'..URL)
return
end
解决方法
是的,像这样:
local mysocket = require(\"socket.http\")
local response,httpCode,header = mysocket.request(URL)
if response == nil then
print(\'The server is unreachable on:\\n\'..URL)
return
end
-- here you do your stuff that\'s supposed to happen when request worked
请求将仅发送一次,如果失败,函数将退出。
,更好的是,当请求失败时,第二个返回是原因:
如果失败,该函数将返回nil,然后返回错误消息。
(摘自http.request的文档)
因此,您可以直接从插槽的嘴中打印问题:
local http = require(\"socket.http\")
local response,header = http.request(URL)
if response == nil then
-- the httpCode variable contains the error message instead
print(httpCode)
return
end
-- here you do your stuff that\'s supposed to happen when request worked