Copy Stdin to Stdout and to Each File Specified

Usage:  tee [-ah-] file1 [ file2 ... ]

   tee is a "pipe-fitting" utility for snapshotting the data passing
   through the middle of a pipeline.

Options:

   -a         Append to any output files that already exist instead
              of truncating and overwriting them.
   -h         Help.
   --         End of Options.