"tail -f" no longer mishandles pipes and fifos. With no operands,
tail now ignores -f if standard input is a pipe, as POSIX requires.
+ When conforming to POSIX 1003.2-1992, tail now handles some obscure
+ cases more correctly, e.g., "tail +cl file" now reads the file "+cl"
+ rather than reporting an error, and "tail - file" no longer reads
+ standard input.
tee now exits when it gets a SIGPIPE signal, as POSIX requires.
To get tee's old behavior, use the shell command "(trap '' PIPE; tee)".