#include <u.h>#include <libc.h>#include <fcall.h> intwaitpid(void){	int n;	char buf[512], *fld[5]; 	n = await(buf, sizeof buf-1);	if(n <= 0)		return -1;	buf[n] = '\0';	if(tokenize(buf, fld, nelem(fld)) != nelem(fld)){		werrstr("couldn't parse wait message");		return -1;	}	return atoi(fld[0]);}