ref: 9e35e814941b08fe29871f7cc8e925bf19ff5f7f
dir: /include/err.h/
#pragma once enum { OK = 0, /* you don't want these mass up with your values */ PERM_DENIED = -128, NAME_TOO_LONG, NO_FILE, FS_NOT_READY, DIR_NOT_EMPTY, NO_MEM, LL_ERR, NO_SUCH_CMD, USAGE, }err;