1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
# b3sum
A command line utility for calculating
[BLAKE3](https://github.com/BLAKE3-team/BLAKE3) hashes, similar to
Coreutils tools like `b2sum` or `md5sum`.
```
Usage: b3sum [OPTIONS] [FILE]...
Arguments:
[FILE]... Files to hash, or checkfiles to check
Options:
--keyed Use the keyed mode, reading the 32-byte key from stdin
--derive-key <CONTEXT> Use the key derivation mode, with the given context string
-l, --length <LEN> The number of output bytes, before hex encoding [default: 32]
--seek <SEEK> The starting output byte offset, before hex encoding [default: 0]
--num-threads <NUM> The maximum number of threads to use
--no-mmap Disable memory mapping
--no-names Omit filenames in the output
--raw Write raw output bytes to stdout, rather than hex
-c, --check Read BLAKE3 sums from the [FILE]s and check them
--quiet Skip printing OK for each checked file
-h, --help Print help (see more with '--help')
-V, --version Print version
```
See also [this document about how the `--check` flag
works](https://github.com/BLAKE3-team/BLAKE3/blob/master/b3sum/what_does_check_do.md).
# Example
Hash the file `foo.txt`:
```bash
b3sum foo.txt
```
Time hashing a gigabyte of data, to see how fast it is:
```bash
# Create a 1 GB file.
head -c 1000000000 /dev/zero > /tmp/bigfile
# Hash it with SHA-256.
time openssl sha256 /tmp/bigfile
# Hash it with BLAKE3.
time b3sum /tmp/bigfile
```
# Installation
Prebuilt binaries are available for Linux, Windows, and macOS (requiring
the [unidentified developer
workaround](https://support.apple.com/guide/mac-help/open-a-mac-app-from-an-unidentified-developer-mh40616/mac))
on the [releases page](https://github.com/BLAKE3-team/BLAKE3/releases).
If you've [installed Rust and
Cargo](https://doc.rust-lang.org/cargo/getting-started/installation.html),
you can also build `b3sum` yourself with:
```
cargo install b3sum
```
On Linux for example, Cargo will put the compiled binary in
`~/.cargo/bin`. You might want to add that directory to your `$PATH`, or
`rustup` might have done it for you when you installed Cargo.
If you want to install directly from this directory, you can run `cargo
install --path .`. Or you can just build with `cargo build --release`,
which puts the binary at `./target/release/b3sum`.
|
