tee(1)

NAME
     tee - pipe fitting

SYNOPSIS
     tee [-i] [-a] [file] . . .

DESCRIPTION
     tee transcribes the standard input to the standard output and makes
     copies in the files.  The sole purpose of tee is to serve, as its name
     implies, as a ``T'' in a pipe.  For example, the command

          grep pattern file1 | tee file2 | wc -l

     catches the output of grep in file2 without having to reexecute the
     command.

     The available options are:

     -i   ignore interrupts;

     -a   causes the output to be appended to the files rather than
          overwriting them.

FILES
     /usr/lib/locale/locale/LC_MESSAGES/uxcore.abi
          language-specific message file [See LANG on environ (5).]