CMP(1)

📦
version 3.12 · 9 versions
, in alpine 3.22, alpine 3.23, alpine 3.24, arch rolling, fedora 43, fedora 44, nixos 26.05, nixpkgs unstable, opensuse-leap 16.0, ubuntu resolute, ubuntu stonking

💖 CMP(1) — the compare-two-files byte-by-byte manual 💖

okay bestie, so this is cmp, a User Commands girlie from the diffutils 3.12 era (April 2025 energy ✨). She's not flashy, she's not loud, she just looks at two files byte by byte and tells you if they match. it's giving forensic scientist. it's giving meticulous. we love her for it 🫶

✨ NAME ✨

cmp — compare two files byte by byte 🦋

🌸 SYNOPSIS 🌸

cmp [OPTION]... FILE1 [FILE2 [SKIP1 [SKIP2]]]

💅 DESCRIPTION 💅

Compare two files byte by byte. that's it, that's the whole job, and she does it flawlessly.

The optional SKIP1 and SKIP2 specify the number of bytes to skip at the beginning of each file (zero by default). so like, if you wanna pretend the first chunk of a file doesn't exist, she's got you 💖

Mandatory arguments to long options are mandatory for short options too. (yes bestie that's a real sentence, it's the classic GNU rule: if a long option needs a value, the short version needs it too, no exceptions, periodt.)

👑 OPTIONS 👑

  • -b, --print-bytes — print differing bytes. show me the receipts, literally 💅
  • -i, --ignore-initial=SKIP — skip first SKIP bytes of both inputs
  • -i, --ignore-initial=SKIP1:SKIP2 — skip first SKIP1 bytes of FILE1 and first SKIP2 bytes of FILE2. yes the same flag twice, she contains multitudes 🧚
  • -l, --verbose — output byte numbers and differing byte values. the full tea ☕
  • -n, --bytes=LIMIT — compare at most LIMIT bytes. girl has a stopping point and honestly? boundaries 🎀
  • -s, --quiet, --silent — suppress all normal output. silent but deadly, no cap 🤫
  • --help — display this help and exit
  • -v, --version — output version information and exit

🔥 THE SUFFIX LORE 🔥

SKIP values may be followed by the following multiplicative suffixes: kB 1000, K 1024, MB 1,000,000, M 1,048,576, GB 1,000,000,000, G 1,073,741,824, and so on for T, P, E, Z, Y.

so lowercase k = powers of 1000, uppercase = powers of 1024, and the pattern just keeps going up through T, P, E, Z, Y like a lil staircase to the heavens 🌈✨

ngl this is the part where people get got: K and kB are NOT the same number. read twice, type once bestie 😭

🌟 STDIN + EXIT STATUS 🌟

If a FILE is '-' or missing, read standard input. (the dash is the classic "yeah just pipe it in" move 🫶)

Exit status is 0 if inputs are the same, 1 if different, 2 if trouble.

  • 0 — twin flames 💖 identical
  • 1 — they're different, it's giving exes 💀
  • 2 — something went wrong, trouble in paradise 😭

🎀 AUTHOR 🎀

Written by Torbjorn Granlund and David MacKenzie. kings, honestly, we stan 👑

💜 REPORTING BUGS 💜

Report bugs to: bug-diffutils@gnu.org

GNU diffutils home page: <https://www.gnu.org/software/diffutils/>

General help using GNU software: <https://www.gnu.org/gethelp/>

if you find a bug, tell them! they wanna know! constructive feedback is self-care fr fr 🌸

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.

like, literally no warranty, bestie. she's free and she's yours to remix, but if it breaks, that's on you 🙈

🌈 SEE ALSO 🌈

The full documentation for cmp is maintained as a Texinfo manual. If the info and cmp programs are properly installed at your site, the command

info cmp

should give you access to the complete manual. go read it, it's the director's cut 💅📖

okay that's the whole page!! you made it to the end, iconic behavior 👑

this has been diffutils 3.12, dated April 2025 — mwah, sending you and your bytes nothing but love 💖✨🎀

📦 where this page comes from