.TH B256SUM 1 blakesum
.SH NAME
b256sum - Compute and check BLAKE-256 message digests
.SH SYNOPSIS
.B b256sum
[-c | -B | -L | -U] [-xz]
.RI [ file "] ..."
.SH DESCRIPTION
Print or check BLAKE-256 checksums.
.SH OPTIONS
The
.B b256sum
utility conforms to the Base Definitions volume of POSIX.1-2017,
.IR "Section 12.2" ,
.IR "Utility Syntax Guidelines" .
.PP
The following options are supported:
.TP
.B -B
Output checksums in binary representation. This suppresses
the filenames and checksum delimiters. Only the checksums
are printed.
.TP
.B -c
Read BLAKE-256 sums from the file and check them against
the files on your systems. The input files files should be
formatted as the output of this program, or similarly.
This is not going to work if any of the filenames in the
input files starts with <space> or <tab>, or if they
contain a <newline>, unless the
.B -z
option is also used.
.TP
.B -L
Output checksums in lower-case hexadecimal representation. (Default)
.TP
.B -U
Output checksums in upper-case hexadecimal representation.
.TP
.B -x
Convert input files from hexadecimal form to binary form
before calculating the checksums.
.TP
.B -z
Lines end with NUL instead of LF. If used with
.BR -c ,
this applies to read files (not the output), but it will
also apply more strict parsing and allow any whitespace
in file names.
.SH OPERANDS
The following operands are supported:
.TP
.I file
File to read. The standard input will be used
.B -
or no
.I file
is specified.
.SH EXIT STATUS
.TP
0
Successful completion.
.TP
1
Checksums did not match or a file did not exist.
.TP
2
An error occurred.
.SH SEE ALSO
.BR bsum (1),
.BR b2sum (1),
.BR b224sum (1),
.BR b384sum (1),
.BR b512sum (1)