#include <u.h>#include <libc.h>#include <auth.h> intprocsetuser(char *user){	char name[32];	Dir dir; 	nulldir(&dir);	dir.uid = user;	snprint(name, sizeof(name), "/proc/%lud/ctl", (ulong)getpid());	if(dirwstat(name, &dir) < 0){		/*		 * this is backwards compatibility code as		 * devproc initially didnt allow changing		 * the user to none.		 */		int fd; 		if(strcmp(user, "none") != 0)			return -1;		fd = open("#c/user", OWRITE|OCEXEC);		if(fd < 0)			return -1;		if(write(fd, "none", 4) != 4){			close(fd);			return -1;		}		close(fd);	}	return 0;}