v7 man page for sum

SUM(1)							      General Commands Manual							    SUM(1)

NAME
       sum - sum and count blocks in a file

SYNOPSIS
       sum file

DESCRIPTION
       Sum  calculates and prints a 16-bit checksum for the named file, and also prints the number of blocks in the file.  It is typically used to
       look for bad spots, or to validate a file communicated over some transmission line.

SEE ALSO
       wc(1)

DIAGNOSTICS
       `Read error' is indistinuishable from end of file on most devices; check the block count.

																	    SUM(1)