search a device for bad blocks

-b block-size
       Specify the size of blocks in bytes.  The default is 1024.

-c number of blocks
       is the number of blocks which are tested at a time.  The default is 64.

-s     Show  the progress of the scan by writing out rough percentage completion of the current badblocks
       pass over the disk.  Note that badblocks may do multiple test passes over the disk, in  particular
       if the -p or -w option is requested by the user.

-w     Use  write-mode  test.  With  this option, badblocks scans for bad blocks by writing some patterns
       (0xaa, 0x55, 0xff, 0x00) on every block of the device,  reading  every  block  and  comparing  the
       contents.  This option may not be combined with the -n option, as they are mutually exclusive.

-v     Verbose mode.  Will write the number of read errors, write errors and data- corruptions to stderr.

Before a command is executed, its input and output may be redirected using a special notation interpreted
by  the  shell.   Redirection  may  also  be used to open and close files for the current shell execution
environment.  The following redirection operators may precede or appear anywhere within a simple  command
or may follow a command.  Redirections are processed in the order they appear, from left to right.

Redirecting Output
    Redirection of output causes the file whose name results from the expansion of  word  to  be  opened  for
    writing  on  file descriptor n, or the standard output (file descriptor 1) if n is not specified.  If the
    file does not exist it is created; if it does exist it is truncated to zero size.

    The general format for redirecting output is:

           [n]>word

    If the redirection operator is >, and the noclobber option to the  set  builtin  has  been  enabled,  the
    redirection  will  fail if the file whose name results from the expansion of word exists and is a regular
    file.  If the redirection operator is >|, or the redirection operator is > and the  noclobber  option  to
    the  set  builtin  command  is  not  enabled, the redirection is attempted even if the file named by word
    exists.