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 no FILE, read  standard  input,
       except if it´s the console. When FILE is -, read standard input even if it´s the console.

       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 file; 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=XXH32, 1=XXH64, 2=XXH128, 3=XXH3. Alternatively,
HASHTYPE 32=XXH32, 64=XXH64, 128=XXH128. Default value is 1 (64bits)

--tag Output in the BSD style.

--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
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.

-b# Specify ID of variant to be tested. Multiple variants can be selected, separated by
a ´,´ comma.

-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. By default,  xxhsum  benchmarks  xxHash  main  variants  on  a
       synthetic  sample  of  100 KB, and print results into 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

       In the following example, the sample to hash is set to 16384 bytes,  the  variants  to  be
       benched  are  selected  by  their  IDs,  and each benchmark test is repeated 10 times, for
       increased accuracy.

           $ xxhsum -b1,2,3 -i10 -B16384

BUGS

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

AUTHOR

       Yann Collet