cksum - Man Page
compute and verify file checksums
Examples (TL;DR)
- Display a 32-bit checksum, size in bytes and filename:
cksum path/to/file
Synopsis
cksum [OPTION]... [FILE]...
Description
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
- --base64
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 size and must be a multiple of 8 for blake2b; must be 224, 256, 384, or 512 for sha2 or sha3
- --raw
emit a raw binary digest, not hexadecimal
- --tag
create a BSD-style checksum (the default)
- --untagged
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
- --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
- --debug
indicate which implementation used
- --help
display this help and exit
- --version
output version information and exit
DIGEST determines the digest algorithm and default output format
- sysv
(equivalent to sum -s)
- bsd
(equivalent to sum -r)
- crc
(equivalent to cksum)
- crc32b
(only available through cksum)
- md5
(equivalent to md5sum)
- sha1
(equivalent to sha1sum)
- sha2
(equivalent to sha{224,256,384,512}sum)
- sha3
(only available through cksum)
- blake2b
(equivalent to b2sum)
- sm3
(only available through cksum)
When checking, the input should be a former output of this program, or equivalent standalone program.
Author
Written by Padraig Brady and Q. Frank Xia.
Reporting Bugs
Report bugs to: bug-coreutils@gnu.org
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
Report any translation bugs to <https://translationproject.org/team/>
Copyright
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.
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), nbdcopy(1), rmd160(3), sha1(3), sha1sum(1), sha2(3), sha224sum(1), sha256sum(1), sha384sum(1), sha512sum(1), unu(1), unu-cksum(1).