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xxhsum(1) -- 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

-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.
-V, --version: Displays xxhsum version and exits
-h, --help: Displays help and exits

Advanced file input options

--files-from, --filelist FILE: Read filenames from FILE and generate hashes for them. stdin is also a valid way to provide filenames (when no FILE or - provided). Valid format is one filename per line, which can include embedded spaces, etc with no need for quotes, escapes, etc. A line commencing with '\' will enable the convention used in the encoding of filenames against output hashes, whereby subsequent \\, \n and \r seqeuences are converted to the single character 0x5C, 0x0A and 0x0D respectively.

The following options are useful only for checksum verification:

-c, --check FILE: Read xxHash sums from FILE and check them
--strict: Return an error code if any line in 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.
-w, --warn: Emit a warning message about each improperly formatted line in FILE.
-q, --quiet: Don't print OK for each successfully verified hash
--status: Don't output anything. Only generate a Status code to show success.

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. 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. 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

Produce a list of files, then generate hashes for that list

$ find . -type f -name '*.[ch]' > c-files.txt
$ xxhsum --files-from c-files.txt

Read the list of files from standard input to avoid the need for an intermediate file

$ find . -type f -name '*.[ch]' | xxhsum --files-from -

Note that if shell expansion, length of argument list, clarity of use of spaces in filenames, etc allow it then the same output as the previous example can be generated like this

$ xxhsum `find . -name '*.[ch]'`

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

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