rm no longer requires read access to the current directory.
+ "sort -o -" now writes to a file named "-" instead of to standard
+ output; POSIX requires this.
+
tail -f no longer mishandles pipes and fifos. With no operands,
tail now ignores -f if standard input is a pipe, as POSIX requires.
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)".
+ Also, "tee -" now writes to standard output instead of to a file named "-".
ls no longer segfaults on systems for which SIZE_MAX != (size_t) -1