redhat man page for sum

sum(n)									sum								    sum(n)

NAME
       sum - calculate a sum(1) compatible checksum

SYNOPSIS
       package require Tcl 8.2

       package require sum ?1.0?

       ::crc::sum ?-format format? message

       ::crc::sum ?-format format? -filename file

DESCRIPTION
       This  package  provides	a Tcl-only implementation of the sum(1) command which calculates a 16 bit checksum value from the input data.  The
       BSD sum algorithm is used by default but the SysV algorithm is also available.

COMMANDS
       ::crc::sum ?-format format? message

       ::crc::sum ?-format format? -filename file
	      The command takes string data or a file name and returns a checksum value calculated using the sum(1) algorithm. The result is  for-
	      matted using the format(n) specifier provided or as an unsigned integer (%u) by default.

OPTIONS
       -filename name
	      Return a checksum for the file contents instead of for parameter data.

       -format string
	      Return the checksum using an alternative format template.

EXAMPLES
       % crc::sum "Hello, World!"
       37287

       % crc::sum -format 0x%X "Hello, World!"
       0x91A7

       % crc::sum -file sum.tcl
       13392

SEE ALSO
       sum(1), cksum(n), crc32(n)

AUTHORS
       Pat Thoyts

KEYWORDS
       sum, cksum, checksum, crc, crc32, cyclic redundancy check, data integrity, security

crc									1.0								    sum(n)