ref: c68d4e43cd22c18199c1b5ea7468e3d9b5b2ad97 dir: /libc/src/tolower.c/
/* See LICENSE file for copyright and license details. */ #define __USE_MACROS #include <ctype.h> int tolower(int c) { return (isupper(c)) ? c & ~0x20 : c; }