detrunc
int detrunc(struct denode *dep, u_long length, int flags, struct ucred *cred);
(void)detrunc(dep, dep->de_FileSize, 0, cred);
error = detrunc(dep, (u_long) 0, 0, NOCRED);
(void)detrunc(ddep, ddep->de_FileSize, 0, NOCRED);
status = B_FROM_POSIX_ERROR(detrunc(fatNode, stat->st_size, 0, NOCRED));
status = B_FROM_POSIX_ERROR(detrunc(existingFatNode, 0, 0, NOCRED));
status = B_FROM_POSIX_ERROR(detrunc(fatNode, 0, 0, NOCRED));
status_t undoStatus = B_FROM_POSIX_ERROR(detrunc(fatNode, origSize, truncFlag, NOCRED));
status = B_FROM_POSIX_ERROR(detrunc(fatNode, static_cast<u_long>(0), 0, NOCRED));