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, xxh3sum is equivalent to xxhsum -H3.

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 mode switch (-t)

       •   xxhsum doesn´t have short binary mode switch (-b)

       •   xxhsum always treats files as binary file

       •   xxhsum has a hash selection 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 (XXH64)

--binary
Read in binary mode.

--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 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