The tee utility faced its first fairway on UNIX platforms, and has been ported to Windows by other providers of UNIX-style utilities. The tee utility actually derives from plumbing. Input and output can be ‘piped’ from one process to another on UNIX and on Windows, and the tee utility creates a tee in the pipe. Thus, in addition to sending output to standard out, you can also redirect it to zero or more files - very useful for keeping a log of a process while simultaneously being able to view its progress and/or send its output on to somewhere else.
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