ref: c3a430e6824a8f1f08f28a8df24b4b64266b06f9
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;
}