packages icon



 XXHSUM(1)                      xxhsum 0.7.4                       XXHSUM(1)
 User Commands                                                 User Commands

                                  July 2020



 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=32bits, 1=64bits, 2=128bits.
           Alternatively, HASHTYPE 32=32bits, 64=64bits, 128=128bits.
           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



                                    - 1 -        Formatted:  August 10, 2020






 XXHSUM(1)                      xxhsum 0.7.4                       XXHSUM(1)
 User Commands                                                 User Commands

                                  July 2020



      -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



                                    - 2 -        Formatted:  August 10, 2020






 XXHSUM(1)                      xxhsum 0.7.4                       XXHSUM(1)
 User Commands                                                 User Commands

                                  July 2020



      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

 SEE ALSO
      md5sum(1)




                                    - 3 -        Formatted:  August 10, 2020