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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 for the blake2 algorithm and must be a multiple of 8
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

The following five options are useful only when verifying checksums:

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

DIGEST determines the digest algorithm and default output format:

(equivalent to sum -s)
(equivalent to sum -r)
(equivalent to cksum)
(equivalent to md5sum)
(equivalent to sha1sum)
(equivalent to sha224sum)
(equivalent to sha256sum)
(equivalent to sha384sum)
(equivalent to sha512sum)
(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.


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


Full documentation <>
or available locally via: info '(coreutils) cksum invocation'

March 2024 GNU coreutils 9.4