CKSUM(1) User Commands CKSUM(1)

cksum - compute and verify file checksums

cksum [OPTION]... [FILE]...

Print or verify checksums. By default use the 32 bit CRC algorithm.

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

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

select the digest type to use. See DIGEST below
emit base64-encoded digests, not hexadecimal
read checksums from the FILEs and check them
digest length in bits; must not exceed the max size and must be a multiple of 8 for blake2b; must be 224, 256, 384, or 512 for sha2 or sha3
emit a raw binary digest, not hexadecimal
create a BSD-style checksum (the default)
create a reversed style checksum, without digest type
end each output line with NUL, not newline, and disable file name escaping

don't fail or report status for missing files
don't print OK for each successfully verified file
don't output anything, status code shows success
exit non-zero for improperly formatted checksum lines
warn about improperly formatted checksum lines
indicate which implementation used
display this help and exit
output version information and exit

(equivalent to sum -s)
(equivalent to sum -r)
(equivalent to cksum)
(only available through cksum)
(equivalent to md5sum)
(equivalent to sha1sum)
(equivalent to sha{224,256,384,512}sum)
(only available through cksum)
(equivalent to b2sum)
(only available through cksum)

When checking, the input should be a former output of this program, or equivalent standalone program.

Written by Padraig Brady and Q. Frank Xia.

Report bugs to: bug-coreutils@gnu.org
GNU coreutils home page: https://www.gnu.org/software/coreutils/
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Copyright © 2025 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.

Full documentation https://www.gnu.org/software/coreutils/cksum
or available locally via: info '(coreutils) cksum invocation'

September 2025 GNU coreutils 9.8