CKSUM(1)

📦
version 9.10 · 5 versions
, in ubuntu stonking

✨ CKSUM(1) — the check-sum bestie era ✨

okay so. cksum is a User Commands girlie and she computes and verifies file checksums. that's it. that's the job. 💅

🎀 NAME 🎀

cksum — compute and verify file checksums 🦋

💖 SYNOPSIS 💖

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

🌸 DESCRIPTION 🌸

Print or verify checksums. By default it uses the 32 bit CRC algorithm, no cap.

With no FILE, or when FILE is -, it reads standard input. (yes bestie, the classic "i'm a pipe now" move 🫶)

Mandatory arguments to long options are mandatory for short options too. the long-option energy is non-negotiable, fr fr.

  • -a, --algorithm=TYPE — select the digest type to use. See DIGEST below 💜
  • --base64 — emit base64-encoded digests, not hexadecimal. different flavor, same facts ✨
  • -c, --check — read checksums from the *FILE*s 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. read those constraints again bestie, they are not a vibe suggestion 😭
  • --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. we're ignoring that, respectfully 🙈
  • --quiet — don't print OK for each successfully verified file. main character energy means no constant validation ✋
  • --status — don't output anything, status code shows success
  • --strict — exit non-zero for improperly formatted checksum lines. strict queen, periodt 💅
  • -w, --warn — warn about improperly formatted checksum lines

🌈 the rest 🌈

  • --debug — indicate which implementation used 🐛
  • --help — display this help and exit
  • --version — output version information and exit

⭐ DIGEST ⭐

DIGEST determines the digest algorithm and default output format. it's giving menu of options:

  • 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 an equivalent standalone program. like, feed it its own leftovers, that's the whole bit 🍓

👑 AUTHOR 👑

Written by Padraig Brady and Q. Frank Xia. absolute icons, we stan 💜

😭 REPORTING BUGS 😭

🔥 SEE ALSO 🔥

Packaged by Ubuntu (9.10-1ubuntu2) Copyright © 2026 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.

this is GNU coreutils 9.10, dated August 2026, and the page is CKSUM(1). byeee bestie, go verify something 💖🌸🦋🎀✨
📦 where this page comes from