CARDOS-TOOL(1)

📦
version 0.27.1 · 17 versions
, in fedora 43, fedora 44

💖 CARDOS-TOOL 💖

okay bestie, so this is the manual page for cardos-tool, part of the OpenSC Tools collection, and it's genuinely one of my faves because it's so straightforward. it's giving "small tool, big main character energy" ✨

🌸 NAME 🌸

cardos-tool — displays information about Card OS-based security tokens, or formats them. that's it, that's the whole job. no cap. 🎀

✨ SYNOPSIS ✨

cardos-tool [OPTIONS]

like, that's the entire synopsis. no positional args, no fuss. we love a clean interface 💅

🦋 DESCRIPTION 🦋

so the cardos-tool utility is used to display information about smart cards and similar security tokens that are based on Siemens Card/OS M4. lowkey iconic honestly — it pokes at your token and tells you what's up, or if you're feeling spicy, it wipes and formats the thing. 🙈

👑 OPTIONS 👑

here's the full menu, bestie. every single one, no skipping:

  • --format, -f — format the card or token. yes, this is the "delete everything" one. handle with care, queen. 🔥
  • --help, -h — print the help message on screen. your lil emergency "wait what do I type" button 🫶
  • --info, -i — display information about the card or token. the vibe check option. run this first, always. ⭐
  • --reader arg, -r arg — the number of the reader to use. by default, the first reader with a present card is used. but here's the cute part: if arg is an ATR, then the reader with a matching card will be chosen. so you can point at a reader by number or by ATR. flexible. slay. 🦋
  • --startkey arg, -s arg — specify the startkey for format. (note: this one's for the format flow, iykyk)
  • --change-startkey arg, -S arg — change the Startkey with the given APDU command. capital S, lowercase s, they are not the same option, bestie. do not mix them up. 😭
  • --verbose, -v — causes cardos-tool to be more verbose. and ooh, the good part: specify this flag several times to enable debug output in the opensc library. stack those -vs like bracelets. 💜
  • --wait, -w — causes cardos-tool to wait for the token to be inserted into the reader. for when your card isn't in yet and the tool is just standing there, patiently, like a good friend. 🌸

🎀 AUTHORS 🎀

cardos-tool was written by Andreas Jellinghaus <aj@dungeon.inka.de>. absolute legend behavior, fr fr. 👑

💀 quick reminder before you go: --format is the destructive one, and --change-startkey wants an APDU command. everything else is just reading and waiting. be safe out there, bestie.

and that's a wrap! this page comes to you from the opensc project, dated 04/19/2026 — so go forth, run that --info, and have the best day. mwah. 💖🌈🧚

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