The argument processing is zhack makes the assumption that getopt()
will not permute argv. This isn't true for the GNU implementation of
getopt() unless the optstring is prefixed with a '+'. In which case
this is equivalent to setting the POSIXLY_CORRECT environment variable
In addition, update the usage() and optstrings to reflect the existing
supported options.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: liaoyuxiangqin <guo.yong33@zte.com.cn>
Closes#5047
9d69e9b268