MSC: int locking( int handle, int mode, long nbytes )
- prototype in io.h, sys\locking.h - handle = opened file handle - nbytes = bytes to lock beginning with current file position - mode = locking mode: = LK_LOCK lock region; on failure waits 1 sec and attempts again; tries 10 times = LK_RLCK same as LK_LOCK = LK_NBLCK lock region; returns immediately on error = LK_NBRLCK lock region; returns immediately on error = LK_UNLCK unlock previously locked region - multiple locks may occur in a single file - overlapping locked regions are not allowed - returns 0 on success or -1 on failure - Turbo C uses lock() and unlock()