Echo server: Difference between revisions
→{{header|Lua}}: Added a non-blocking, non-busy implementation.
(→{{header|Lua}}: I fixed error with require("socket"); made code more clear.) |
(→{{header|Lua}}: Added a non-blocking, non-busy implementation.) |
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{{works with|Lua|5.3}}
{{libheader|LuaSocket}}
This implementation doesn't rely on coroutines because they're an additional (often confusing) notion that could make the example needlessly hard to understand. Instead it uses a table of not-quite-non-blocking socket client objects (they block for 4 milliseconds), which is iterated over to check on whether each one has either a line to echo or an error to warrant deletion.▼
<lang Lua>local socket = require("socket")
local function has_value(tab, value)
for i, v in ipairs(tab) do
if v == value then return i end
end
return false
end
local function checkOn(client)
local line, err = client:receive()
if line then
client:send(line .. "\n")
end
if err and err ~= "timeout" then
print(tostring(client) .. " " .. err)
client:close()
return true -- end this connection
end
return false -- do not end this connection
end
local server = assert(socket.bind("*",12321))
server:settimeout(0) -- make non-blocking
local connections = { } -- a list of the client connections
while true do
local newClient = server:accept()
if newClient then
newClient:settimeout(0) -- make non-blocking
table.insert(connections, newClient)
end
local readList = socket.select({server, table.unpack(connections)})
for _, conn in ipairs(readList) do
if conn ~= server and checkOn(conn) then
table.remove(connections, has_value(connections, conn))
end
end
end</lang>
----
▲
<lang Lua>local socket=require("socket")
Line 1,561 ⟶ 1,601:
table.insert(connections, newClient)
end</lang>
=={{header|Nim}}==
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