Undocumented
Functions defined in the headers, but not in the wiki
SDL_abs
SDL_asprintf
SDL_atof
SDL_atoi
SDL_bsearch
SDL_bsearch_r
SDL_calloc
SDL_crc16
SDL_crc32
SDL_free
SDL_getenv
SDL_iconv
SDL_iconv_close
SDL_iconv_open
SDL_itoa
SDL_lltoa
SDL_ltoa
SDL_malloc
SDL_memcmp
SDL_memcpy
SDL_memmove
SDL_memset
SDL_memset4
SDL_qsort
SDL_qsort_r
SDL_realloc
SDL_setenv
SDL_snprintf
SDL_sscanf
SDL_strcasestr
SDL_strchr
SDL_strdup
SDL_strlcat
SDL_strlcpy
SDL_strlen
SDL_strndup
SDL_strnlen
SDL_strnstr
SDL_strrchr
SDL_strrev
SDL_strstr
SDL_strtod
SDL_strtok_r
SDL_strtol
SDL_strtoll
SDL_strtoul
SDL_strtoull
SDL_swprintf
SDL_uitoa
SDL_ulltoa
SDL_ultoa
SDL_utf8strlcpy
SDL_utf8strlen
SDL_utf8strnlen
SDL_vasprintf
SDL_vsnprintf
SDL_vsscanf
SDL_vswprintf
SDL_wcsdup
SDL_wcslcat
SDL_wcslcpy
SDL_wcslen
SDL_wcsnlen
SDL_wcsnstr
SDL_wcsstr
SDL_wcstol