NAME

sum − sum and count blocks in 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 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

wc(1). 

DIAGNOSTICS

“Read error” is indistinguishable from end of file on most devices; check the block count. 

May 16, 1980