Command:   sum - compute the checksum and block count of a file
Syntax:    sum file
Flags:     (none)
Examples:  sum /user/ast/xyz        # Checksum /user/ast/xyz

     Sum computes the checksum of one or more files.  It is  most  often
used  to  see  if  a file copied from another machine has been correctly
received.  This program works best  when  both  machines  use  the  same
checksum algorithm.  See also crc.