MD5SUM(1)

📦
version 9.10 · 5 versions
, in ubuntu stonking

💅 MD5SUM — the glow-up edition ✨

okay bestie, so you know that MD5SUM(1) page in the User Commands manual? yeah. we're doing it. but cute. and honestly it's giving legacy icon energy, so let's get into it 🫶

🌸 NAME 🌸

md5sum — compute and check MD5 message digest. that's it. that's the whole vibe. she computes, she checks, she slays ✨

🎀 SYNOPSIS 🎀

md5sum [OPTION]... [FILE]...

like. options. then files. in that order. periodt 💅

🦋 DESCRIPTION 🦋

so what she does is print or check MD5 (128-bit) checksums. and real talk — this is the legacy interface to the cksum utility. she's the OG, the ancestor, the grandmother of checksum tools, and we respect her for it 👑

if you hand her no FILE at all, or if FILE is literally just -, she reads from standard input. no file? no problem. stdin it is 💖

here are her options, one by one, no skips:

  • -b, --binary — reads in binary mode
  • -c, --check — reads checksums from the FILEs and checks them. this is the "am I being lied to" mode fr fr
  • --tag — creates a BSD-style checksum. fancy. different. iconic
  • -t, --text — reads in text mode, and yes that's the default, she's chill like that
  • -z, --zero — ends each output line with NUL, not newline, and disables file name escaping. very script-friendly of her ngl

✨ OPTIONS ✨

🧚 the five that only matter when you're verifying

bestie listen. the next five options are useful only when verifying checksums. if you're not checking, they're just sitting there. still valid. still gorgeous. just not doing anything 🙈

  • --ignore-missing — doesn't fail or report status for missing files. if the file ghosted you, she's not gonna make it a whole thing 💀
  • --quiet — doesn't print OK for each successfully verified file. no celebration, no confetti, just silence. lowkey mysterious
  • --status — doesn't output anything at all. the status code shows success. she's the strong silent type and honestly? obsessed 🎀
  • --strict — exits non-zero for improperly formatted checksum lines. she will call it out. she will be strict. that's the name, that's the energy
  • -w, --warn — warns about improperly formatted checksum lines. like --strict but she talks about it first, very communicative 💅
  • --help — displays this help and exits. the classic. the friend who explains the assignment and then leaves
  • --version — outputs version information and exits. she'll tell you who she is, then she's out 🌈

⭐ the actual math-y part

the sums are computed as described in RFC 1321. when checking, the input should be a former output of this program — meaning she reads her own homework, which is valid here, i promise.

the default mode is to print a line with:

  1. the checksum,
  2. a space,
  3. a character indicating the input mode — '*' for binary, ' ' for text or where binary is insignificant,
  4. and the name — for each FILE.

also, on GNU systems, there is no difference between binary mode and text mode. same thing. no drama. we love a peaceful queen 💜

💀 BUGS 💀

girl. do NOT use the MD5 algorithm for security related purposes. this is the most important sentence in the whole page, bestie, do not skip it.

instead, use an SHA-2, SHA-3, or BLAKE2 algorithm — all implemented in the cksum(1) program. MD5 for security is giving locked door made of paper. it's not that she's bad, she's just not that 🔥🚫

👑 AUTHOR 👑

written by Ulrich Drepper, Scott Miller, and David Madore. three legends. one tool. ate. 💅✨

😭 REPORTING BUGS 😭

found something busted? tell the people:

they want to hear from you, fr fr 🫶

🌈 SEE ALSO 🌈

and that's the whole page, bestie 💖 this was GNU coreutils 9.10, dated August 2026, and the manual section was MD5SUM(1) — now go checksum something responsibly and never use MD5 for secrets, i'm serious, mwah 🎀✨

📦 where this page comes from