#include <u.h>#include <libc.h> voidmain(int argc, char **argv){	Dir d; 	if(argc != 3){		fprint(2, "usage: trunc file size\n");		exits("usage");	} 	nulldir(&d);	d.length = strtoull(argv[2], 0, 0);	if(dirwstat(argv[1], &d) < 0)		sysfatal("dirwstat: %r");	exits(0);}