ref: 14b919faf8e69fb8c06bb397b5a87c2b9f00c3bb
dir: /sys/src/ape/lib/ap/plan9/ftruncate.c/
#include "lib.h"
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include "dir.h"
int
ftruncate(int fd, off_t length)
{
	Dir d;
	if(length < 0){
		errno = EINVAL;
		return -1;
	}
	_nulldir(&d);
	d.length = length;
	if(_dirfwstat(fd, &d) < 0){
		_syserrno();
		return -1;
	}
	return 0;
}