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:
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xxhsum doesn´t have text mode switch (-t)
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xxhsum doesn´t have short binary mode switch (-b)
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xxhsum always treats files as binary file
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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
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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)
- -sSEED, --seed SEED
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Set the unsigned decimal seed used for hashing and checksum verification. The seed is not stored in checksum files, so the same value must be provided when verifying seeded checksums. Default value is 0.
- --binary
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Accepted for compatibility. This option has no effect because xxhsum always reads files in binary mode.
- --tag
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Output in the BSD style.
- --little-endian
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Set output hexadecimal checksum value as little endian convention. By default, value is displayed as big endian.
- -V, --version
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Displays xxhsum version and exits
- -h, --help
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Displays help and exits
- --
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Treat all following arguments as file names. This is useful for file names beginning with -.
Advanced file input options
- --files-from, --filelist FILE
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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 beginning with byte 0x5C enables filename unescaping. Subsequent byte sequences 0x5C 0x5C, 0x5C 0x6E, and 0x5C 0x72 are converted to the single bytes 0x5C, 0x0A, and 0x0D, respectively.
Checksum verification options:
- -c, --check FILE
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Read xxHash sums from FILE and check them
- --strict
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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
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Emit a warning message about each improperly formatted line in FILE.
- -q, --quiet
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Don´t print OK for each successfully verified hash. In benchmark mode, don´t display the version header.
- --status
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Don´t output anything. Only generate a Status code to show success.
- --ignore-missing
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Don´t fail or report status for missing files.
Benchmark options:
- -b
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Benchmark mode. See EXAMPLES for details.
- -b#
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Specify ID of variant to be tested. Multiple variants can be selected, separated by a ´,´ comma.
- -BBLOCKSIZE
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Only useful for benchmark mode (-b). See EXAMPLES for details. BLOCKSIZE specifies benchmark mode´s test data block size in bytes and accepts the suffixes K, KB, KiB, M, MB, and MiB. All suffixes use powers of 1024: K, KB, and KiB multiply by 1024, while M, MB, and MiB multiply by 1048576. Default value is 102400.
- -iITERATIONS
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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
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$ 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
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$ xxhsum -H0 foo bar baz > xyz.xxh32 $ xxhsum -H1 foo bar baz > qux.xxh64
Read xxHash sums from specific files and check them
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$ xxhsum -c xyz.xxh32 qux.xxh64
Produce a list of files, then generate hashes for that list
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$ 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
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$ 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
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$ 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.
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$ 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.
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$ xxhsum -b1,2,3 -i10 -B16384
BUGS
Report bugs at: https://github.com/Cyan4973/xxHash/issues/
AUTHOR
Yann Collet