Returns a textual description of the host operating system. The format is as follows:
<API name> (<kernel name> [kernel version] kernel) version <API version>, <machine architecture> architecture
API name can be one of the following:
The
kernel name is whatever the operating system says it is (eg; 9x, NT, Linux) and the
kernel version is whatever the operating system thinks it is.
API version for Windows generally follows 4.x for Windows 95/NT until Windows 2000 where it becomes 5.x. For POSIX, it is always POSIX.2 meaning v2 but the API version is whatever the operating system reports itself as compliant with. The point to remember is this function is concerned with
API version which is in fact all you need know about as well even in non-portable code.
Lastly, machine architecture currently can be one of: i486, PowerPC, Alpha, IA64, AMD64, unknown.