Print a checksum for a file.
'sum' is provided for compatibility; 'cksum' is preferable in new applications.
Syntax sum [options]... [file]... Options -r Use the default (BSD compatible) algorithm. This option is included for compatibility with the System V 'sum'. Unless '-s' was also given, it has no effect. -s --sysv Compute checksums using an algorithm compatible with System V 'sum''s default, and print file sizes in units of 512-byte blocks.
'sum' prints the checksum for each FILE followed by the number
of blocks in the file (rounded up). If more than one FILE is given, file names
are also printed (by default). (With the '--sysv' option, corresponding file
name are printed when there is at least one file argument.)
By default, GNU 'sum' computes checksums using an algorithm compatible with BSD 'sum' and prints file sizes in units of 1024-byte blocks.
“Winning takes talent; to repeat takes character” ~ John Wooden
cksum - Print CRC checksum and byte counts.
sha256sum - Compute and check SHA256 (256-bit) checksums.