SHA256SUM(1)

📦
version 9.10 · 5 versions
, in ubuntu stonking

💖 SHA256SUM — compute and check SHA256 message digest 💖

okay bestie, gather round, because this one is iconic and also extremely useful and also an elder. it's sha256sum, it lives in the GNU coreutils family, and it's the legacy interface to the cksum utility. so like, it's the cool older sibling that still shows up to every family dinner. 🫶

✨ SYNOPSIS ✨

sha256sum [OPTION]... [FILE]...

🌸 DESCRIPTION 🌸

What does it do? It prints or checks SHA256 (256-bit) checksums. that's the whole vibe. cryptographic fingerprints for your files, and it will absolutely tell you if something got messed with. no cap. 🔥

If you give it no FILE at all, or if FILE is literally just -, it reads from standard input. so pipe away, gorgeous. 🦋

Okay now the options, and there are a bunch, so buckle up. every single one is listed, I am not skipping a single crumb. 💅

  • -b, --binary — read in binary mode ✨
  • -c, --check — read checksums from the FILEs and check them 👑 this is the "verify my stuff" mode
  • --tag — create a BSD-style checksum 🎀
  • -t, --text — read in text mode (default) 🌸
  • -z, --zero — end each output line with NUL, not newline, and disable file name escaping 🌈 this one is very "for the scripts" of it

💜 the following five options are useful only when verifying checksums 💜

gonna be so real, these five only matter when you're in check mode. exam season options only. 📚

  • --ignore-missing — don't fail or report status for missing files 🙈
  • --quiet — don't print OK for each successfully verified file 💀 (silence, but make it verification)
  • --status — don't output anything, status code shows success 🎯 all the info, none of the yapping
  • --strict — exit non-zero for improperly formatted checksum lines 😤
  • -w, --warn — warn about improperly formatted checksum lines 🚨

⭐ the classic two, always on the menu ⭐

  • --help — display this help and exit 🫶
  • --version — output version information and exit 🎀

So the sums themselves are computed as described in FIPS-180-2. that's the actual spec, not vibes. ✨

When you're checking, the input should be a former output of this program. like, feed it its own receipts. 🧾 The default mode is to print a line with: checksum, a space, a character indicating input mode ('*' for binary, ' ' for text or where binary is insignificant), and name for each FILE.

And here's a little plot twist that lowkey changes everything: there is no difference between binary mode and text mode on GNU systems. 😌 so on GNU, -b and -t are basically twins. fr fr.

👑 AUTHOR 👑

Written by Ulrich Drepper, Scott Miller, and David Madore. absolute legends, we stan. 🩷

🚨 REPORTING BUGS 🚨

Found something broken? Don't suffer in silence, tell the devs:

🔍 SEE ALSO 🔍

  • cksum(1) — the other one, the original one, go say hi 🫶

Full documentation lives at <https://www.gnu.org/software/coreutils/sha256sum>, or you can get it locally with:

info '(coreutils) sha2 utilities'
💖 legal moment, bestie, pay attention: 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. so like… it's yours to remix, but if it breaks, it's not their problem. 💅

and that's the whole page, GNU coreutils 9.10, August 2026 — SHA256SUM(1), out. slay, go hash something. 💖✨🦋

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