How to limit the amount of characters in a Lua string

Question

I have a question: how do I make the lua_tostring function limit the amount of entries.

For example 8 characters limit:

poppy_name = "command"; // OK, within the limit;
poppy_name = "commander"; // Fail, Is out of range, show a message the permitted limit.

I searched I couldn't find anymore, is there a way to limit the lua_tostring?

catwell · Accepted Answer · 2015-11-29T15:40:50.343

3

Use lua_tolstring to obtain the string length, then use lua_error or luaL_error if the string is too long.

size_t arg_len;
lua_tolstring(L, 1, &arg_len);
if (arg_len > 8) return luaL_error(L, "argument too long");

edited Nov 29 '15 at 15:40

answered Nov 28 '15 at 20:01

catwell

4

@MarcosSilva `size_t *myLen; lua_tolstring(L, 1, &myLen); if( myLen > 8 ) raise hell` – hjpotter92 Nov 28 '15 at 21:57
understand by your example hjpotter92, case solved. Thank you – Marcos Silva Nov 28 '15 at 23:18
@Marcos Silva if his answer helped you, accept it by pressing that green checkmark next to it, this is to help future users with the same problem to find the answer quicker. – warspyking Nov 29 '15 at 00:10
Added an example to the answer, thank you @hjpotter92 – catwell Nov 29 '15 at 13:06
It should be `size_t arg_len`, not `size_t *arg_len`. Unfortunately the edit to fix that is too short ... – siffiejoe Nov 29 '15 at 13:59

1 Answers1