xxHash/xxhsum.1

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.TH "XXHSUM" "1" "October 2019" "xxhsum 0.7.2" "User Commands"
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.SH "NAME"
\fBxxhsum\fR \- print or check xxHash non\-cryptographic checksums
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.SH "SYNOPSIS"
\fBxxhsum [<OPTION>] \.\.\. [<FILE>] \.\.\.\fR
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.br
\fBxxhsum \-b [<OPTION>] \.\.\.\fR
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.P
\fBxxh32sum\fR is equivalent to \fBxxhsum \-H0\fR
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.br
\fBxxh64sum\fR is equivalent to \fBxxhsum \-H1\fR
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.br
\fBxxh128sum\fR is equivalent to \fBxxhsum \-H2\fR
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.SH "DESCRIPTION"
Print or check xxHash (32, 64 or 128 bits) checksums\. When \fIFILE\fR is \fB\-\fR, read standard input\.
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.P
\fBxxhsum\fR supports a command line syntax similar but not identical to md5sum(1)\. Differences are: \fBxxhsum\fR doesn\'t have text/binary mode switch (\fB\-b\fR, \fB\-t\fR); \fBxxhsum\fR always treats file as binary file; \fBxxhsum\fR has hash bit width switch (\fB\-H\fR);
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.P
As xxHash is a fast non\-cryptographic checksum algorithm, \fBxxhsum\fR should not be used for security related purposes\.
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.P
\fBxxhsum \-b\fR invokes benchmark mode\. See \fIOPTIONS\fR and \fIEXAMPLES\fR for details\.
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.SH "OPTIONS"
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.TP
\fB\-V\fR, \fB\-\-version\fR
Display xxhsum version and exits
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.TP
\fB\-H\fR\fIHASHTYPE\fR
Hash selection\. \fIHASHTYPE\fR means \fB0\fR=32bits, \fB1\fR=64bits, \fB2\fR=128bits\. Default value is \fB1\fR (64bits)
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.TP
\fB\-q\fR, \fB\-\-quiet\fR
Remove status messages like "Loading \.\.\." written to \fBstderr\fR \.
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.TP
\fB\-\-little\-endian\fR
Set output hexadecimal checksum value as little endian convention\. By default, value is displayed as big endian\.
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.TP
\fB\-h\fR, \fB\-\-help\fR
Display help and exit
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.P
\fBThe following four options are useful only when verifying checksums (\fB\-c\fR)\fR
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.TP
\fB\-c\fR, \fB\-\-check\fR
Read xxHash sums from the \fIFILE\fRs and check them
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.TP
\fBq\fR, \fB\-\-quiet\fR
Exit non\-zero for improperly formatted checksum lines
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.TP
\fB\-\-strict\fR
Don\'t print OK for each successfully verified file
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.TP
\fB\-\-status\fR
Don\'t output anything, status code shows success
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.TP
\fB\-w\fR, \fB\-\-warn\fR
Warn about improperly formatted checksum lines
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.P
\fBThe following options are useful only benchmark purpose\fR
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.TP
\fB\-b\fR
Benchmark mode\. See \fIEXAMPLES\fR for details\.
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.TP
\fB\-B\fR\fIBLOCKSIZE\fR
Only useful for benchmark mode (\fB\-b\fR)\. See \fIEXAMPLES\fR for details\. \fIBLOCKSIZE\fR specifies benchmark mode\'s test data block size in bytes\. Default value is 102400
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.TP
\fB\-i\fR\fIITERATIONS\fR
Only useful for benchmark mode (\fB\-b\fR)\. See \fIEXAMPLES\fR for details\. \fIITERATIONS\fR specifies number of iterations in benchmark\. Single iteration lasts approximately 1000 milliseconds\. Default value is 3
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.SH "EXIT STATUS"
\fBxxhsum\fR exit \fB0\fR on success, \fB1\fR if at least one file couldn\'t be read or doesn\'t have the same checksum as the \fB\-c\fR option\.
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.SH "EXAMPLES"
Output xxHash (64bit) checksum values of specific files to standard output
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.IP "" 4
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.nf

$ xxhsum \-H1 foo bar baz
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.fi
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.IP "" 0
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.P
Output xxHash (32bit and 64bit) checksum values of specific files to standard output, and redirect it to \fBxyz\.xxh32\fR and \fBqux\.xxh64\fR
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.IP "" 4
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.nf

$ xxhsum \-H0 foo bar baz > xyz\.xxh32
$ xxhsum \-H1 foo bar baz > qux\.xxh64
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.fi
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.IP "" 0
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.P
Read xxHash sums from specific files and check them
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.IP "" 4
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.nf

$ xxhsum \-c xyz\.xxh32 qux\.xxh64
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.fi
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.IP "" 0
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.P
Benchmark xxHash algorithm for 16384 bytes data in 10 times\. \fBxxhsum\fR benchmarks all xxHash variants and output results to standard output\.
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.br
First column means algorithm, second column is source data size in bytes, third column is number of hashes generated per second (throughput), and finally last column translates speed in mega\-bytes per seconds\.
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.IP "" 4
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.nf

$ xxhsum \-b \-i10 \-B16384
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.fi
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.IP "" 0
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.SH "BUGS"
Report bugs at: https://github\.com/Cyan4973/xxHash/issues/
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.SH "AUTHOR"
Yann Collet
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.SH "SEE ALSO"
md5sum(1)