So recently I've tried to use the ndless sdk to make some stuff for my calculator. Nspireio is pretty cool and all, but I really can't make sense of the documentation. I figured out how to use nio_printf as that's basically printf, but there's no nio_scanf... what am I supposed to do to take input?

Oh, gets without a size argument ? Not very secure

Feature request for nspireio, if it doesn't exist: add nio_getsn(), and rewrite
#define nio_gets(arg) nio_getsn(arg, sizeof(arg))

text is indeed the output variable.

Oh, gets without a size argument ? Not very secure

There is nio_fgets, which has a size argument. nio_gets is just there because it is ANSI C.

So recently I've tried to use the ndless sdk to make some stuff for my calculator. Nspireio is pretty cool and all, but I really can't make sense of the documentation. I figured out how to use nio_printf as that's basically printf, but there's no nio_scanf... what am I supposed to do to take input?

If you just want to use nspireio as a simple fullscreen console, you should take a look at the replace-stdio demo. Nspireio provides some functions from stdio.h, so you could just look at its documentation here.

@Roondak you can use nio_fgets and then use sscanf() (which is a syscall) to parse the string easily.

@ElementCoder the gets function doesn't receive the size of the buffer as a parameter; in standard C, it just writes until it sees a newline or EOF, which can lead to buffer overflows.
In NspireIO, nio_gets just calls nio_fgets with a size parameter of 100, so if you have a buffer of size at least 100, you're safe; otherwise, you must use nio_fgets.

EDIT: compu added nio_scanf and nio_sscanf