1xxhsum(1) -- print or check xxHash non-cryptographic checksums 2============================================================== 3 4SYNOPSIS 5-------- 6 7`xxhsum [<OPTION>] ... [<FILE>] ...` 8`xxhsum -b [<OPTION>] ...` 9 10`xxh32sum` is equivalent to `xxhsum -H0` 11`xxh64sum` is equivalent to `xxhsum -H1` 12`xxh128sum` is equivalent to `xxhsum -H2` 13 14 15DESCRIPTION 16----------- 17 18Print or check xxHash (32, 64 or 128 bits) checksums. 19When no <FILE>, read standard input, except if it's the console. 20When <FILE> is `-`, read standard input even if it's the console. 21 22`xxhsum` supports a command line syntax similar but not identical to md5sum(1). 23Differences are: 24`xxhsum` doesn't have text/binary mode switch (`-b`, `-t`); 25`xxhsum` always treats files as binary file; 26`xxhsum` has a hash bit width switch (`-H`); 27 28As xxHash is a fast non-cryptographic checksum algorithm, 29`xxhsum` should not be used for security related purposes. 30 31`xxhsum -b` invokes benchmark mode. See [OPTIONS](#OPTIONS) and [EXAMPLES](#EXAMPLES) for details. 32 33OPTIONS 34------- 35 36* `-V`, `--version`: 37 Displays xxhsum version and exits 38 39* `-H`<HASHTYPE>: 40 Hash selection. <HASHTYPE> means `0`=32bits, `1`=64bits, `2`=128bits. 41 Alternatively, <HASHTYPE> `32`=32bits, `64`=64bits, `128`=128bits. 42 Default value is `1` (64bits) 43 44* `--tag`: 45 Output in the BSD style. 46 47* `--little-endian`: 48 Set output hexadecimal checksum value as little endian convention. 49 By default, value is displayed as big endian. 50 51* `-h`, `--help`: 52 Displays help and exits 53 54**The following four options are useful only when verifying checksums (`-c`)** 55 56* `-c`, `--check` <FILE>: 57 Read xxHash sums from <FILE> and check them 58 59* `-q`, `--quiet`: 60 Don't print OK for each successfully verified file 61 62* `--strict`: 63 Return an error code if any line in the file is invalid, 64 not just if some checksums are wrong. 65 This policy is disabled by default, 66 though UI will prompt an informational message 67 if any line in the file is detected invalid. 68 69* `--status`: 70 Don't output anything. Status code shows success. 71 72* `-w`, `--warn`: 73 Emit a warning message about each improperly formatted checksum line. 74 75**The following options are useful only benchmark purpose** 76 77* `-b`: 78 Benchmark mode. See [EXAMPLES](#EXAMPLES) for details. 79 80* `-b#`: 81 Specify ID of variant to be tested. 82 Multiple variants can be selected, separated by a ',' comma. 83 84* `-B`<BLOCKSIZE>: 85 Only useful for benchmark mode (`-b`). See [EXAMPLES](#EXAMPLES) for details. 86 <BLOCKSIZE> specifies benchmark mode's test data block size in bytes. 87 Default value is 102400 88 89* `-i`<ITERATIONS>: 90 Only useful for benchmark mode (`-b`). See [EXAMPLES](#EXAMPLES) for details. 91 <ITERATIONS> specifies number of iterations in benchmark. Single iteration 92 lasts approximately 1000 milliseconds. Default value is 3 93 94EXIT STATUS 95----------- 96 97`xxhsum` exit `0` on success, `1` if at least one file couldn't be read or 98doesn't have the same checksum as the `-c` option. 99 100EXAMPLES 101-------- 102 103Output xxHash (64bit) checksum values of specific files to standard output 104 105 $ xxhsum -H1 foo bar baz 106 107Output xxHash (32bit and 64bit) checksum values of specific files to standard 108output, and redirect it to `xyz.xxh32` and `qux.xxh64` 109 110 $ xxhsum -H0 foo bar baz > xyz.xxh32 111 $ xxhsum -H1 foo bar baz > qux.xxh64 112 113Read xxHash sums from specific files and check them 114 115 $ xxhsum -c xyz.xxh32 qux.xxh64 116 117Benchmark xxHash algorithm. 118By default, `xxhsum` benchmarks xxHash main variants 119on a synthetic sample of 100 KB, 120and print results into standard output. 121The first column is the algorithm, 122the second column is the source data size in bytes, 123the third column is the number of hashes generated per second (throughput), 124and finally the last column translates speed in megabytes per second. 125 126 $ xxhsum -b 127 128In the following example, 129the sample to hash is set to 16384 bytes, 130the variants to be benched are selected by their IDs, 131and each benchmark test is repeated 10 times, for increased accuracy. 132 133 $ xxhsum -b1,2,3 -i10 -B16384 134 135BUGS 136---- 137 138Report bugs at: https://github.com/Cyan4973/xxHash/issues/ 139 140AUTHOR 141------ 142 143Yann Collet 144 145SEE ALSO 146-------- 147 148md5sum(1) 149