在Linux中定义的头文件是EINVAL，ENOMEM等？

It’s said that the error numbers like EINVAL, ENOMEM, etc. are defined in errno.h, but I can’t find them in errno.h, I also searched some directories under /usr/include, still can’t find them. I can use these macros without any issue in my C code. Anyone can tell me where are them?It’s said that the error numbers like EINVAL, E