软件包：libio-tee-perl（0.66-2）
module for multiplexing output to multiple output handles
IO::Tee objects can be used to multiplex input and output in two different ways. The first way is to multiplex output to zero or more output handles. The IO::Tee constructor, given a list of output handles, returns a tied handle that can be written to. When written to (using print or printf), the IO::Tee object multiplexes the output to the list of handles originally passed to the constructor. As a shortcut, you can also directly pass a string or an array reference to the constructor, in which case IO::File::new is called for you with the specified argument or arguments.
The second way is to multiplex input from one input handle to zero or more output handles as it is being read. The IO::Tee constructor, given an input handle followed by a list of output handles, returns a tied handle that can be read from as well as written to. When written to, the IO::Tee object multiplexes the output to all handles passed to the constructor, as described in the previous paragraph. When read from, the IO::Tee object reads from the input handle given as the first argument to the IO::Tee constructor, then writes any data read to the output handles given as the remaining arguments to the constructor.