Tired of repeating myself, I wrote this simple module to grab user input (hopefully) securely.

Currently, only integer and single character input are supported.

All functions are member of prompt structure, and should be called with dot operator, e.g. prompt.yesno("Are you hungry? ").

• static int intrange(char* prompt, int min, int max)

  Integer prompt: min <= input <= max.

  When min > max, you'll get an endless loop.

• static int intbetween(char* prompt, int min, int max)

  Integer prompt: min < input < max.

  When min > max, you'll get an endless loop.

• static bool binopt(char* prompt, char opt_y, char opt_n)

  Binary options prompt, with case-insensitive input.

• static bool yesno(char* prompt)

  Y/N prompt, a shorthand for bin_prompt(), with Y or N input.

musl-gcc needs static flag, e.g.

musl-gcc -static demo.c prompt.c -o demo.out

Otherwise, valgrind will throw an error: __libc_freeres: symbol not found.

This error has been around sometime (GIYBF), but I haven't digged it any further.

Tested with musl 1.1.24-1 and valgrind 3.150 on Ubuntu 20.04.2 LTS (WSL 2).

Any contribution will be absolutely appreciated.