B3SUM(1)

💖 B3SUM 💖

okay bestie, welcome to B3SUM(1) — the manual page for b3sum version 1.8.7 🦋 this is your little BLAKE3 hashing bestie and she is fast, she is fierce, and she is about to make your checksums cute. no cap.

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✨ SYNOPSIS ✨

b3sum [OPTIONS] [FILE]...

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🌸 DESCRIPTION 🌸

🎀 Arguments:

• [FILE]... — the files you wanna hash, or the checkfiles you wanna check 💅

when you don't give her any file at all, or when you hand her a -, she reads from standard input. periodt.

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💅 OPTIONS 💅

• --keyed — turns on the keyed mode, and she reads that 32-byte key straight from stdin 🔑
• --derive-key <CONTEXT> — turns on the key derivation mode, using the context string you give her ✨
  • 🚫 Cannot be used with --keyed. pick a lane bestie, she can't do both.
• -l, --length <LEN> — how many output bytes you want, before the hex encoding happens 📏
  • [default: 32]
• --seek <SEEK> — the starting output byte offset, also before hex encoding 👀
  • [default: 0]
• --num-threads <NUM> — the max number of threads she's allowed to use 🧵
  • by default this is literally the number of logical cores. if you skip this flag entirely, or if its value is 0, then RAYON_NUM_THREADS gets respected too. iykyk.
• --no-mmap — disables memory mapping 🚫🗺️
  • lowkey important: right now this also disables multithreading. so yeah, that's the tradeoff bestie.
• --no-names — omits filenames from the output 🙈
• --raw — writes the raw output bytes straight to stdout instead of hex 🍓
  • --no-names is implied in this case. and in this case, only a single input is allowed. one (1) file. that's the rule.
• --tag — outputs BSD-style checksums, shaped like this: BLAKE3 ([FILE]) = [HASH] 🏷️
• -c, --check — reads BLAKE3 sums from the [FILE]s and checks them ✅
• --quiet — skips printing OK for every single file she checks 🤫
  • must be used with --check. she said no quiet without a check, that's the vibe.
• -h, --help — prints help (and hey, you can see a summary with '-h') 📖
• -V, --version — prints version 👑

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ngl the whole thing is literally just hashing, but she does it so well. main character energy fr fr 💜

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and that's the whole page, bestie!! 🫶 this was b3sum version 1.8.7, dated August 2026, from the B3SUM(1) manual — go forth and hash, you absolute icon 👑🌈⭐