LCKDO(1)

📦
version 0.70 · 3 versions
  • 0.70 · debian bookworm, debian trixie, epel 10, epel 9, fedora 43, fedora 44, nixos 26.05, nixpkgs unstable, opensuse-leap 16.0, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking (latest)
  • 0.70 · alpine 3.24
  • 0.70 · arch rolling
, in debian bookworm, debian trixie, epel 10, epel 9, fedora 43, fedora 44, nixos 26.05, nixpkgs unstable, opensuse-leap 16.0, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

✨ LCKDO ✨

okay bestie, gather round, because lckdo is one of those lil moreutils gems that's giving quietly iconic 💅

🌸 NAME 🌸

lckdo — run a program with a lock held 🔒

🦋 SYNOPSIS 🦋

lckdo [options] {lockfile} {program} [arguments]

💖 DESCRIPTION 💖

So basically lckdo runs a program with a lock held, and the whole point is to stop multiple processes from running in parallel — like, no cap, it's a bouncer at the club door of your process table 🎀. Use it just like nice or nohup, fr fr.

okay so here's the sad part 😭 — now that util-linux contains a similar command named flock, lckdo is deprecated, and it will be removed from some future version of moreutils. it's giving retirement era, and we're not okay about it 💀

👑 OPTIONS 👑

  • -w — if the lock is already held by another process, just wait for it to complete instead of failing immediately. patience is a virtue bestie 🫶
  • -W {sec} — the same as -w, but wait not more than sec seconds. so like, waiting with a timer ⏰
  • -e — execute the program directly without forking and waiting (keeps an extra file descriptor open). lowkey efficient ✨
  • -E {nnn} — set the file descriptor number to keep open when exec()ing (implies -e). you pick the number, she keeps the door open 🚪
  • -n — do not create the lock file if it does not exist. no lock file? no problem, she's not making one 🙈
  • -q — produce no output if the lock is already held. silent treatment, but make it intentional 💅
  • -s — lock in shared (read) mode. we're all reading together, cozy 🌸
  • -x — lock in exclusive (write) mode (default). one at a time, main character energy 👑
  • -t — test for lock existence. just checking, no commitment 🧚

🌈 EXIT STATUS 🌈

If the lock was successfully acquired, the return value is that of the program invoked by lckdo — so whatever your program says goes, she's just the messenger 💌.

If the lock couldn't be acquired, EX_TEMPFAIL is returned. 😭

If there was a problem opening/creating or locking the lock file, EX_CANTCREAT or EX_OSERR will be returned. 💀

⭐ AUTHOR ⭐

Michael Tokarev — we love a legend 🫶

and that's the whole page bestie!! this one's from moreutils, dated 2007-08-15 — yes she's an elder icon and yes she still slays 🎀✨ bye ily 🦋

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