ref: cf9a3c2ad5a1e1a371cad0b6d5fc4164a68caf76
dir: /sys/src/ape/lib/ap/plan9/umask.c/
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
/*
* No such concept in plan9, but supposed to be always successful
*/
mode_t
umask(mode_t)
{
return 0;
}