Provided by: libsdl3-doc_3.2.8+ds-1_all 

NAME
SDL_tolower - Convert low-ASCII English letters to lowercase.
HEADER FILE
Defined in SDL3/SDL_stdinc.h
SYNOPSIS
#include "SDL3/SDL.h" int SDL_tolower(int x);
DESCRIPTION
WARNING : Regardless of system locale, this will only convert ASCII values 'A' through 'Z' to lowercase. This function returns the lowercase equivalent of x . If a character cannot be converted, or is already lowercase, this function returns x .
FUNCTION PARAMETERS
x character value to check.
RETURN VALUE
Returns lowercase version of x, or x if no conversion available.
THREAD SAFETY
It is safe to call this function from any thread.
AVAILABILITY
This function is available since SDL 3.2.0. Simple Directmedia Layer SDL 3.2.8 SDL_tolower(3)