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cksum - Man Page

compute and verify file checksums

Examples (TL;DR)


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.

-a,  --algorithm=TYPE

select the digest type to use.  See DIGEST below.


emit base64-encoded digests, not hexadecimal

-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


emit a raw binary digest, not hexadecimal


create a BSD-style checksum (the default)


create a reversed style checksum, without digest type

-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


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

-w,  --warn

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.

Reporting Bugs

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

See Also

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

Referenced By

b2sum(1), cksum(n), md5.3bsd(3), md5sum(1), mtree(5), rmd160(3), sha1(3), sha1sum(1), sha2(3), sha224sum(1), sha256sum(1), sha384sum(1), sha512sum(1), unu(1), unu-cksum(1).

July 2024 GNU coreutils 9.5