xxhsum(1) -- print or check xxHash non-cryptographic checksums

SYNOPSIS

xxhsum [] ... [] ...
xxhsum -b [] ...

xxh32sum is equivalent to xxhsum -H0
xxh64sum is equivalent to xxhsum -H1

DESCRIPTION

Print or check xxHash (32 or 64bit) checksums. When is -, read standard input.

xxhsum supports a command line syntax similar but not indentical to md5sum(1). Differences are: xxhsum doesn't have text/binary mode switch (-b, -t); xxhsum always treats file as binary file; xxhsum has hash bit width 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

-V, --version: Display xxhsum version
-H: Hash selection. means 0=32bits, 1=64bits. Default value is 1 (64bits)
--little-endian: Set output hexadecimal checksum value as little endian convention. By default, value is displayed as big endian.
-h, --help: Display help and exit

The following four options are useful only when verifying checksums (-c)

-c, --check: Read xxHash sums from the s and check them
--quiet: Exit non-zero for improperly formatted checksum lines
--strict: Don't print OK for each successfully verified file
--status: Don't output anything, status code shows success
-w, --warn: Warn about improperly formatted checksum lines

The following options are useful only benchmark purpose

-b: Benchmark mode. See EXAMPLES for details.
-B: Only useful for benchmark mode (-b). See EXAMPLES for details. specifies benchmark mode's test data block size in bytes. Default value is 102400
-i: Only useful for benchmark mode (-b). See EXAMPLES for details. specifies number of iterations in benchmark. Single iteration takes at least 2500 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

Benchmark xxHash algorithm for 16384 bytes data in 10 times. xxhsum benchmarks xxHash algorithm for 32-bit and 64-bit and output results to standard output. First column means algorithm, second column is source data size in bytes, last column means hash generation speed in mega-bytes per seconds.

$ xxhsum -b -i10 -B16384

BUGS

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

AUTHOR

Yann Collet

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