In general we only have a limited subset of the standard libc functions available for development inside the kernel. And we have very limited concordance with Linux and that only be co-incidence. Generally you need to grep around in the Kernel.framework/Headers directory to find that appropriate APIs. A trick I use to work out exactly what functions are actually in the kernel is to do a 'nm -pgo /mach_kernel'. This will list every symbol that is in the kernel. Note however NOT all of these are exported as APIs but you will find your printf variants, str* & mem* routines etc. As Stephan suggested it is usually better to code to the standard of the subsystem you will be developing for. Could you let us know what problem it is you are trying to solve inside the xnu kernel. Please read the available documentation especially the Conceptual stuff. Godfrey On Apr 20, , at 5:09, Stephan Lichtenauer wrote: Am 20.04.2004 um 09:27 schrieb yetty: Thank you for your good advice. But what I need is the functions that I can use for kernel programming. For example, printf() is the function used in user space, while printk() is the function used in kernel space.(This is true for Linux but I do not know whether it is true for Mac OS X.) What I want to know is the functions used in kernel programming. Thank you very muck! Ye Wenxi Tokyo Hi, I suggest you first look at all the documentation that comes with the OS X Developer Tools in /Developer/Documentation/DarwinCoreOS and especially /Documentation/DarwinCoreOS/Conceptual on your harddisk (install them from the CD that came with 10.3 or download them from developer.apple.com (a free registration is required in this case), you need them anyway if you have not yet installed them. Then you might want to check out the various example kernel extensions in the Darwin CVS I suggested in my last email. Cheers Stephan _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored. _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.