sunos man page for sum

sum(1B) 					     SunOS/BSD Compatibility Package Commands						   sum(1B)

NAME
       sum - calculate a checksum for a file

SYNOPSIS
       /usr/ucb/sum file...

DESCRIPTION
       sum  calculates	and  displays a 16-bit checksum for the named file and displays the size of the file in kilobytes. It is typically used to
       look for bad spots, or to validate a file communicated over some transmission line. The checksum is calculated by an  algorithm	which  may
       yield different results on machines with 16-bit ints and machines with 32-bit ints, so it cannot always be used to validate that a file has
       been transferred between machines with different-sized ints.

USAGE
       See largefile(5) for the description of the behavior of sum when encountering files greater than or equal to 2 Gbyte ( 2**31 bytes).

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWscpu			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       sum(1), wc(1), attributes(5), largefile(5)

DIAGNOSTICS
       Read error is indistinguishable from EOF on most devices; check the block count.

NOTES
       sum and /usr/bin/sum (see sum(1)) return different checksums.

       This utility is obsolete.

SunOS 5.10							    8 Nov 1995								   sum(1B)