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