You are using socket.http, but try to access https URL. luasocket doesn’t handle HTTPS protocol, so it sends a request to the default port 80 instead and gets a redirect to HTTPS link (same link); this goes for several times (as the URL doesn’t really change), and in the end luasocket gives up producing the … Read more
There is no way to do that without iterating. If you find yourself needing to do this frequently, consider building an inverse index: local index={} for k,v in pairs(values) do index[v]=k end return index[“a”]
The programming language is named Lua, it is officially not a acronym. Lua is a common word meaning Moon in Portuguese. The language is named like this because a previous programming language at PUC (in early development phase) was already named SOL for Simple Object Language. And since SOL means Sun in Portuguese, its successor … Read more
It looks like LuaDec itself was last updated for Lua 5.0.2. A new version targeting Lua 5.1.x bytecode has been released as LuaDec51. The wiki is always a good place to start looking for resources as mentioned by f3lix. The mailing list is also a good place to ask. Do note that it is relatively … Read more
When you call lua_next, the second argument should be the index of the table. Since you’re just pushing the table onto the stack with lua_getglobal(L, “level”); after that call your stack will look like -1: table “level” (not +1, since the stack is read going down). Then you call lua_pushnil(L); so your stack will be … Read more
maybe lua-cjsonis your friend: install e.g. through luarocks: $sudo luarocks install lua-cjson then in lua: local json = require(‘cjson’) local tab = json.decode(json_string) json_string = json.encode(tab)
Lua doesn’t provide a standard sleep function, but there are several ways to implement one, see Sleep Function for detail. For Linux, this may be the easiest one: function sleep(n) os.execute(“sleep ” .. tonumber(n)) end In Windows, you can use ping: function sleep(n) if n > 0 then os.execute(“ping -n ” .. tonumber(n+1) .. ” … Read more
[I was going to post this as a comment on John Cromartie’s post, but didn’t realize you couldn’t use formatting in a comment.] I agree. Dropping it to a shell with os.execute() will definitely work but in general making shell calls is expensive. Wrapping some C code will be much quicker at run-time. In C/C++ … Read more
Try function file_exists(name) local f=io.open(name,”r”) if f~=nil then io.close(f) return true else return false end end but note that this code only tests whether the file can be opened for reading.
ipairs() and pairs() are slightly different, as you can see on the manual reference. A less-technical description could be that: ipairs() returns index-value pairs and is mostly used for numeric tables. The non-numeric keys are ignored as a whole, similar to numeric indices less than 1. In addition, gaps in between the indexes lead to … Read more