Ubuntu Manpage: xxhsum - print or check xxHash non-cryptographic checksums

NAME

       xxhsum - print or check xxHash non-cryptographic checksums

SYNOPSIS

       xxhsum [<OPTION>]... [<FILE>]...
       xxhsum -b [<OPTION>]...

       xxh32sum is equivalent to xxhsum -H0
       xxh64sum is equivalent to xxhsum -H1
       xxh128sum is equivalent to xxhsum -H2

DESCRIPTION

       Print or check xxHash (32, 64 or 128 bits) checksums. When FILE is -, read standard input.

       xxhsum  supports a command line syntax similar but not identical to md5sum(1). Differences
       are: xxhsum doesn´t have text/binary mode switch (-b, -t); xxhsum always treats  files  as
       binary files; xxhsum has a hash bit width switch (-H);

       As  xxHash  is  a fast non-cryptographic checksum algorithm, xxhsum should not be used for
       security related purposes.

       xxhsum -b invokes benchmark mode. See OPTIONS and EXAMPLES for details.

OPTIONS

-V, --version
Displays xxhsum version and exits

-HHASHTYPE
Hash selection. HASHTYPE means 0=32bits, 1=64bits, 2=128bits. Default value is 1
(64bits)

-q, --quiet
Remove status messages like "Loading..." written to stderr .

--little-endian
Set output hexadecimal checksum value as little endian convention. By default,
value is displayed as big endian.

-h, --help
Displays help and exits

The following four options are useful only when verifying checksums (-c)

-c, --check FILE
Read xxHash sums from FILE and check them

-q, --quiet
On top of removing status messages written to stderr, also don´t print OK for each
successfully verified file

--strict
Return an error code if any line in the file is invalid, not just if some checksums
are wrong. This policy is disabled by default, though UI will prompt an
informational message if any line in the file is detected invalid.

--status
Don´t output anything. Status code shows success.

-w, --warn
Emit a warning message about each improperly formatted checksum line.

The following options are useful only benchmark purpose

-b Benchmark mode. See EXAMPLES for details.

-BBLOCKSIZE
Only useful for benchmark mode (-b). See EXAMPLES for details. BLOCKSIZE specifies
benchmark mode´s test data block size in bytes. Default value is 102400

-iITERATIONS
Only useful for benchmark mode (-b). See EXAMPLES for details. ITERATIONS specifies
number of iterations in benchmark. Single iteration lasts approximately 1000
milliseconds. Default value is 3

EXIT STATUS

       xxhsum exit 0 on success, 1 if at least one file couldn´t be read or doesn´t have the same
       checksum as the -c option.

EXAMPLES

       Output xxHash (64bit) checksum values of specific files to standard output

           $ xxhsum -H1 foo bar baz

       Output  xxHash (32bit and 64bit) checksum values of specific files to standard output, and
       redirect it to xyz.xxh32 and qux.xxh64

           $ xxhsum -H0 foo bar baz > xyz.xxh32
           $ xxhsum -H1 foo bar baz > qux.xxh64

       Read xxHash sums from specific files and check them

           $ xxhsum -c xyz.xxh32 qux.xxh64

       Benchmark xxHash algorithm for 16384 bytes data in 10 times. xxhsum benchmarks all  xxHash
       variants and output results to standard output.
       The first column is the algorithm, the second column is the source data size in bytes, the
       third column is the number of hashes generated per second (throughput), and  finally,  the
       last column translates speed in megabytes per second.

           $ xxhsum -b -i10 -B16384

BUGS

       Report bugs at: https://github.com/Cyan4973/xxHash/issues/

AUTHOR

       Yann Collet