xxhsum man page

xxhsum — print or check xxHash non-cryptographic checksums


xxhsum [<OPTION>] ... [<FILE>] ...
xxhsum -b [<OPTION>] ...

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


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

xxhsum supports a command line syntax similar but not identical 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.


-V, --version

Display xxhsum version


Hash selection. HASHTYPE means 0=32bits, 1=64bits. Default value is 1 (64bits)


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 FILEs and check them


Exit non-zero for improperly formatted checksum lines


Don´t print OK for each successfully verified file


Don´t output anything, status code shows success

-w, --warn

Warn about improperly formatted checksum lines

The following options are useful only benchmark purpose


Benchmark mode. See Examples for details.


Only useful for benchmark mode (-b). See Examples for details. BLOCKSIZE specifies benchmark mode´s test data block size in bytes. Default value is 102400


Only useful for benchmark mode (-b). See Examples for details. ITERATIONS 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.


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


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


Yann Collet

See Also



September 2017 xxhsum 0.6.3 User Commands