linux - sum (1)

       sum - checksum and count the blocks in a file

       sum [-rs] [--sysv] [--help] [--version] [file...]

       This  manual  page  documents the GNU version of sum.  sum
       computes a 16-bit checksum for each  named  file,  or  the
       standard  input if none are given or when a file named `-'
       is given.  It prints the checksum for each file along with
       the number of blocks in the file (rounded up).  By default
       each corresponding file name is also printed if  at  least
       two arguments are specified.  With the --sysv option, cor-
       responding file name are printed when there  is  at  least
       one  file  argument.   By  default,  the  GNU sum computes
       checksums using an algorithm that is compatible  with  the
       BSD sum and prints file sizes in units of 1K blocks.

   OPTIONS
       -r     Use  the  default (BSD compatible) algorithm.  This
              option is included for compatibility with the  Sys-
              tem V sum.  Unless the -s option was also given, it
              has no effect.

       -s, --sysv
              Compute checksums using an algorithm that  is  com-
              patible  with  the  one  the  System  V sum uses by
              default and print file sizes in units  of  512-byte
              blocks instead of 1K.

       --help Print  a  usage message and exit with a status code
              indicating success.

       --version
              Print version information on standard  output  then
              exit.