SUM(1V)

NAME
sum - calculate a checksum for a file

SYNOPSIS
sum filename

SYSTEM V SYNOPSIS
/usr/5bin/sum [ -r ] filename

AVAILABILITY
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.

DESCRIPTION
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.

SEE ALSO
wc(1)

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