32v 1m sum
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SUM(1) UNIX Programmer's Manual SUM(1)
sum - sum and count blocks in a file
_S_u_m 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.
`Read error' is indistinuishable from end of file on most devices; check the block count.