flock( ) 函数示例

close databases
open database (home( ) + 'samples\data\testdata')
use products  && 打开 products 表
set reprocess to 3 seconds
select * from products into table newprods
if flock( )
	*** 初始化 ***
	replace all in_stock  with 0.00
	replace all on_order with 0.00
	wait 'initialization complete' window nowait
else
	*** 文件已锁定，警告用户 ***
	wait window 'unable to open products file; try again later!' nowait
endif
browse fields in_stock, on_order && 显示 newprods 表
use
erase newprods.dbf