SUM(1)
NAME
sum − sum and count blocks in a file
USAGE
sum file
DESCRIPTION
Sum calculates and prints a 16-bit checksum for the named file. It also prints the number of blocks in the file. Typically, sum is most helpful in looking for bad spots in a file, or in validating a file communicated over a transmission line.
DIAGNOSTICS
"Read error" is indistinguishable from end-of-file on most devices. Check the block count.