sum - calculate a checksum for a file
SYSTEM V SYNOPSIS
/usr/5bin/sum [ -r ] filename
The System V version of this command is available with the System V
software installation option. Refer to for information on how to
install optional software.
sum calculates and displays a 16-bit checksum for the named file, and
also 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.
SYSTEM V DESCRIPTION
sum calculates and prints a 16-bit checksum for the named file, and
also prints the number of 512-byte blocks in the file. It is typically
used to look for bad spots, or to validate a file communicated over
some transmission line. This algorithm is independent of the size of
ints on the machine.
SYSTEM V OPTIONS
The option -r causes the (machine-dependent) algorithm used by the non-
System V sum to be used in computing the checksum.
Read error is indistinguishable from EOF on most devices; check the
9 September 1987 SUM(1V)