sum—Checksum and count the blocks in a file
sum [-rs] [–sysv] [–help] [–version] [file…]
This manual page documents the GNU version of sum. sum computes a 16-bit checksum for each named file, or the standard input if none are given or when a file named – is given. It prints the checksum for each file along with the number of blocks in the file (rounded up). By default, each corresponding filename is also printed if at least two arguments are specified. With the —sysv option, corresponding filenames are printed when there is at least one file argument. By default, the GNU sum computes checksums using an algorithm that is compatible with the BSD sum and prints file sizes in units of 1K blocks.
|-r||Use the default (BSD-compatible) algorithm. This option is included for compatibility with the System V sum. Unless the -s option was also given, it has no effect.|
|-s, —sysv||Compute checksums using an algorithm that is compatible with the one the System V sum uses by default and print file sizes in units of 512-byte blocks instead of 1K.|
|–help||Print a usage message and exit with a non-zero status.|
|–version||Print version information on standard output, then exit.|