xxhsum(1)

1XXHSUM(1)                        User Commands                       XXHSUM(1)
2
3
4

NAME

6       xxhsum - print or check xxHash non-cryptographic checksums
7

SYNOPSIS

9       xxhsum [<OPTION>] ... [<FILE>] ... xxhsum -b [<OPTION>] ...
10
11       xxh32sum  is  equivalent to xxhsum -H0 xxh64sum is equivalent to xxhsum
12       -H1 xxh128sum is equivalent to xxhsum -H2
13

DESCRIPTION

15       Print or check xxHash (32, 64 or 128 bits)  checksums.  When  no  FILE,
16       read  standard  input, except if it´s the console. When FILE is -, read
17       standard input even if it´s the console.
18
19       xxhsum supports a command line syntax  similar  but  not  identical  to
20       md5sum(1). Differences are: xxhsum doesn´t have text/binary mode switch
21       (-b, -t); xxhsum always treats files as binary file; xxhsum has a  hash
22       bit width switch (-H);
23
24       As xxHash is a fast non-cryptographic checksum algorithm, xxhsum should
25       not be used for security related purposes.
26
27       xxhsum -b invokes benchmark mode. See OPTIONS and EXAMPLES for details.
28

OPTIONS

30       -V, --version
31              Displays xxhsum version and exits
32
33       -HHASHTYPE
34              Hash selection. HASHTYPE means  0=32bits,  1=64bits,  2=128bits.
35              Alternatively,   HASHTYPE   32=32bits,  64=64bits,  128=128bits.
36              Default value is 1 (64bits)
37
38       --tag  Output in the BSD style.
39
40       --little-endian
41              Set output hexadecimal checksum value as little  endian  conven‐
42              tion. By default, value is displayed as big endian.
43
44       -h, --help
45              Displays help and exits
46
47       The  following  four  options  are useful only when verifying checksums
48       (-c)
49
50       -c, --check FILE
51              Read xxHash sums from FILE and check them
52
53       -q, --quiet
54              Don´t print OK for each successfully verified file
55
56       --strict
57              Return an error code if any line in the  file  is  invalid,  not
58              just  if  some  checksums  are wrong. This policy is disabled by
59              default, though UI will prompt an informational message  if  any
60              line in the file is detected invalid.
61
62       --status
63              Don´t output anything. Status code shows success.
64
65       -w, --warn
66              Emit  a warning message about each improperly formatted checksum
67              line.
68
69       The following options are useful only benchmark purpose
70
71       -b     Benchmark mode. See EXAMPLES for details.
72
73       -b#    Specify ID of variant to be tested.  Multiple  variants  can  be
74              selected, separated by a ´,´ comma.
75
76       -BBLOCKSIZE
77              Only  useful  for benchmark mode (-b). See EXAMPLES for details.
78              BLOCKSIZE specifies benchmark mode´s test  data  block  size  in
79              bytes. Default value is 102400
80
81       -iITERATIONS
82              Only  useful  for benchmark mode (-b). See EXAMPLES for details.
83              ITERATIONS specifies number of iterations in  benchmark.  Single
84              iteration  lasts  approximately 1000 milliseconds. Default value
85              is 3
86

EXIT STATUS

88       xxhsum exit 0 on success, 1 if at least one file couldn´t  be  read  or
89       doesn´t have the same checksum as the -c option.
90

EXAMPLES

92       Output  xxHash  (64bit)  checksum  values of specific files to standard
93       output
94
95
96
97           $ xxhsum -H1 foo bar baz
98
99
100
101       Output xxHash (32bit and 64bit) checksum values of  specific  files  to
102       standard output, and redirect it to xyz.xxh32 and qux.xxh64
103
104
105
106           $ xxhsum -H0 foo bar baz > xyz.xxh32
107           $ xxhsum -H1 foo bar baz > qux.xxh64
108
109
110
111       Read xxHash sums from specific files and check them
112
113
114
115           $ xxhsum -c xyz.xxh32 qux.xxh64
116
117
118
119       Benchmark  xxHash  algorithm. By default, xxhsum benchmarks xxHash main
120       variants on a synthetic sample of 100 KB, and print results into  stan‐
121       dard  output.  The  first column is the algorithm, the second column is
122       the source data size in bytes, the third column is the number of hashes
123       generated  per  second (throughput), and finally the last column trans‐
124       lates speed in megabytes per second.
125
126
127
128           $ xxhsum -b
129
130
131
132       In the following example, the sample to hash is set to 16384 bytes, the
133       variants  to  be  benched are selected by their IDs, and each benchmark
134       test is repeated 10 times, for increased accuracy.
135
136
137
138           $ xxhsum -b1,2,3 -i10 -B16384
139
140
141

BUGS

143       Report bugs at: https://github.com/Cyan4973/xxHash/issues/
144

AUTHOR

146       Yann Collet
147