man > b2sum(1)

Che Dong

⚡ TLDR: b2sum (tldr-pages)

Calculate BLAKE2 cryptographic checksums.

Calculate the BLAKE2 checksum for one or more files
b2sum {{path/to/file1 path/to/file2 ...}}
Calculate and save the list of BLAKE2 checksums to a file
b2sum {{path/to/file1 path/to/file2 ...}} > {{path/to/file.b2}}
Calculate a BLAKE2 checksum from `stdin`
{{command}} | b2sum
Read a file of BLAKE2 checksums and filenames and verify all files have matching checksums
b2sum {{-c|--check}} {{path/to/file.b2}}
Only show a message for missing files or when verification fails
b2sum {{-c|--check}} --quiet {{path/to/file.b2}}
Only show a message when verification fails, ignoring missing files
b2sum --ignore-missing {{-c|--check}} --quiet {{path/to/file.b2}}
Check a known BLAKE2 checksum of a file
echo {{known_blake2_checksum_of_the_file}} {{path/to/file}} | b2sum {{-c|--check}}

B2SUM(1) User Commands B2SUM(1)

NAME
b2sum - compute and check BLAKE2 message digest

SYNOPSIS
b2sum [OPTION]... [FILE]...

DESCRIPTION
Print or check BLAKE2b (512-bit) checksums.

With no FILE, or when FILE is -, read standard input.

Mandatory arguments to long options are mandatory for short options too.

-b, --binary
read in binary mode

-c, --check
read checksums from the FILEs and check them

-l, --length=BITS
digest length in bits; must not exceed the max for the blake2 algorithm and must be a
multiple of 8

--tag create a BSD-style checksum

-t, --text
read in text mode (default)

-z, --zero
end each output line with NUL, not newline, and disable file name escaping

The following five options are useful only when verifying checksums:
--ignore-missing
don't fail or report status for missing files

--quiet
don't print OK for each successfully verified file

--status
don't output anything, status code shows success

--strict
exit non-zero for improperly formatted checksum lines

-w, --warn
warn about improperly formatted checksum lines

--help display this help and exit

--version
output version information and exit

The sums are computed as described in RFC 7693. When checking, the input should be a former
output of this program. The default mode is to print a line with: checksum, a space, a char‐
acter indicating input mode ('*' for binary, ' ' for text or where binary is insignificant),
and name for each FILE.

Note: There is no difference between binary mode and text mode on GNU systems.

AUTHOR
Written by Padraig Brady and Samuel Neves.

REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>

COPYRIGHT
Copyright © 2023 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later
<https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to
the extent permitted by law.