ref: cde4b93a27af60da423b3ed387de5f7a31ba32b7
dir: /sys/src/libc/9sys/getuser.c/
#include <u.h>
#include <libc.h>
char *
getuser(void)
{
static char user[64];
char name[32];
Dir *dir;
snprint(name, sizeof(name), "/proc/%lud/status", (ulong)getpid());
if((dir = dirstat(name)) == nil)
return "none";
snprint(user, sizeof(user), "%s", dir->uid);
free(dir);
return user;
}