/usr/share/zfs/zfs-tests/bin/manipulate_user_buffer: invalid option -- '-'
Unrecognized option: --
/usr/share/zfs/zfs-tests/bin/manipulate_user_buffer: invalid option -- 'l'
Unrecognized option: -l
/usr/share/zfs/zfs-tests/bin/manipulate_user_buffer: invalid option -- 'p'
Unrecognized option: -p
usage /usr/share/zfs/zfs-tests/bin/manipulate_user_buffer -f filename [-b blocksize] [-e wr_error_expected]
         [-n numblocks] [-p randompattern] -r read_op
         -w write_op [-h help]

Testing whether checksum verify works correctly for O_DIRECT.
when manipulating the contents of a userspace buffer.

    filename:       File to read or write to.
    blocksize:      Size of each block to write (must be at
                    least >= 512).
    err_expected:   Whether write() is expected to return EIO
                    while manipulating the contents of the
                    buffer.
    numblocks:      Total number of blocksized blocks to
                    write.
    read_op:        Perform reads to the filename file while
                    while manipulating the buffer contents
    write_op:       Perform writes to the filename file while
                    manipulating the buffer contents
    randompattern:  Fill data buffer with random data for
                    writes. Default behavior is to fill the
                    buffer with known data pattern (0xdeadbeef)
    help:           Print usage information and exit.

    Required parameters:
    filename
    read_op or write_op

    Default Values:
    blocksize       -> 131072
    wr_err_expexted -> false
    numblocks       -> 100
    randompattern   -> false