CKSUM(1)

Writes an Ethernet CRC of each file, its size in bytes, and its name, separated by tabs, followed by newlines, to the standard output stream. If no files, use the standard input stream and omit the name. If a file is "-", use the standard input stream.

The files' size is also included in the sum, so files beginning with runs of NUL bytes produce different results.

EXAMPLES

$ echo POSIX.2 | cksum
3842620415      8
$ echo POSIX.2 | cksum 'IEEE P1003.2 Draft 11.2—September 1991.pdf' -
2938529873      3226947 IEEE P1003.2 Draft 11.2—September 1991.pdf
3842620415      8       -

STANDARDS

Conforms to $IEEE No Std 1003.1 - 2024 Po Do Tn . EN P OSIX Ns .1 Dc Pc; the field separater can be any nonempty sequence of spaces and tabs . The CRC polynomial is % x^{32} + x^{26} + x^{23} + x^{22} + x^{16} + x^{12} + x^{11} + x^{10} + x^{8} + x^{7} + x^{5} + x^{4} + x^{2} + x + 1 %, the same one used by . St - iso 8802 - 3 Pq Ethernet . . Pp All bytes of the file are summed, followed by non - zero bytes of its length \underset{the}{,} least significant . . . Sh HISTORY Created in . St - p 1003.2 - 92, as . Nm \sum implementations were irreconcilable, cf . . Xr \sum 1 . . . EQ$

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STANDARDS