sum(1) — USER COMMANDS
NAME
sum − print checksum and block count of a file
SYNOPSIS
sum [−r] file
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. The option -r causes an alternate algorithm to be used in computing the checksum.
SEE ALSO
DIAGNOSTICS
“Read error” is indistinguishable from end of file on most devices; check the block count.
— Directory and File Management Utilities