S6-FDHOLDER-STORE(8)

📦 version 2.15.1.0, in nixpkgs unstable

💖 s6-fdholder-store(8) — the system manager's manual, but make it cute 💖

okay so bestie, welcome to s6-fdholder-store, a page from the System Manager's Manual that's about handing a file descriptor to a daemon so it can babysit it for you. yes, that's a real job. slay. 🎀

✨ NAME ✨

s6-fdholder-store — connect to an s6-fdholderd(8) daemon listening on a Unix domain socket, and give it a copy of one of its open file descriptors for the daemon to hold. 💅

like, it's a whole handoff. you hand the fd over, the daemon holds it, everybody wins. 🫶

🌸 SYNOPSIS 🌸

s6-fdholder-store [-d fd] [-T fdtimeout] [-t timeout] path id

🦋 DESCRIPTION 🦋

s6-fdholder-store connects to an s6-fdholderd(8) server process listening on path.

it then tries to pass a copy of its standard input — or of its descriptor fd, if you said so — to the server, with identifier id. that id is the name tag the daemon files it under, so you can ask for it back later. iconic behavior honestly. ✨

👑 OPTIONS 👑

  • -d fd — store descriptor number fd. by default, fd is 0, which is literally the program's stdin, so the default vibe is "here's my stdin, please hold". 🍓
  • -T fdtimeout — the descriptor gets stored with an expiration time of fdtimeout milliseconds. meaning: the s6-fdholderd(8) daemon will close it and get rid of it after that time. by default, fdtimeout is 0, which means infinite — no expiration time, it lives forever (or at least until someone deletes it). ⭐
  • -t timeout — if the operation can't be processed within timeout milliseconds, then fail with an error message. ngl, communications with the server should be near-instant, so this option is only here to protect users against programming errors (connecting to the wrong socket, for instance). it's giving seatbelt energy. 🚗💨

💀 EXIT STATUS 💀

  • 0 — Success. ate and left no crumbs. 🔥
  • 1 — The server denied the operation. the meanings of the error messages are explained in s6-fdholder-error-codes(7), so go read that if you're confused. 🙈
  • 100 — Wrong usage. you called it weird, bestie. 😭
  • 111 — System call failed — this includes attempting to connect to a nonexistent socket, or one where no s6-fdholderd(8) daemon is listening. 👻

🌈 EXAMPLES 🌈

s6-ipcserver-socketbinder /tmp/mysocket s6-fdholder-store
/service/fdholderd/s MYSOCKET

okay so what this does: it will open a Unix domain socket, bind it to /tmp/mysocket and listen to incoming connections, then give it to an s6-fdholderd(8) instance listening on /service/fdholderd/s, with no expiration date, with the “MYSOCKET” identifier. 🎀

another program will be able to retrieve the socket later, using s6-fdholder-retrieve(8). it's the circle of fd life. 🦋

💜 SEE ALSO 💜

this man page is ported from the authoritative documentation at: https://skarnet.org/software/s6/s6-fdholder-store.html — go give it a read if you want the original author's exact words. 📚

🧚 AUTHORS 🧚

  • Laurent Bercot
  • Alexis <flexibeast@gmail.com> (man page port)
bestie reminder: this page is Debian's, dated September 29, 2021, and it's page S6-FDHOLDER-STORE(8) of the System Manager's Manual. mwah, go store some descriptors 💋💖
📦 where this page comes from