FADVISE(1)

✨ fadvise — the girlies' guide ✨

okay so bestie, welcome to fadvise(1) 💖 this is a User Commands manual page, and it's about a lil utility that uses the posix_fadvise(2) system call. yes it's a real thing. yes it's giving kernel-adjacent main character energy. let's get into it 🫶

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🌸 NAME 🌸

fadvise — a utility to use the posix_fadvise(2) system call ✨

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🎀 SYNOPSIS 🎀

fadvise [-a advice] [-o offset] [-l length] filename

fadvise [-a advice] [-o offset] [-l length] -d file-descriptor

two whole ways to run her. pick your fighter 💅

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🦋 DESCRIPTION 🦋

so fadvise is a simple command that wraps the posix_fadvise(2) system call, and what that call does is predeclare an access pattern for file data. that's it. that's the whole vibe. you're basically telling the kernel "hey girl, here's how i'm gonna be reading this file, just so you know" 🔥

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💜 OPTIONS 💜

• -d, --fd file-descriptor — apply the advice to the file specified with the file descriptor instead of opening a file specified with a file name. fd girlies, this one's for you 🫶
• -a, --advice advice — the actual advice you're handing over. peep the command output with the --help option to see the available values for advice, bestie, because that's where they live. if you omit this option, dontneed is used as the default advice. no cap 💅
• -o, --offset offset — specifies the beginning offset of the range, in bytes. if you omit this option, 0 is used as default advice. (yes, it says "default advice" in the original and we are respectfully passing that along verbatim 😭)
• -l, --length length — specifies the length of the range, in bytes. if you omit this option, 0 is used as default advice. same energy, same wording, iconic 🙈
• -h, --help — display help text and exit. the classic.
• -V, --version — display version and exit. also the classic.

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⭐ EXIT STATUS ⭐

fadvise has the following exit status values:

• 0 — success 🎉 ate, no crumbs
• 1 — unspecified failure 💀 not the vibe

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👑 AUTHORS 👑

Masatake YAMATO <yamato@redhat.com>

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🌈 SEE ALSO 🌈

posix_fadvise(2)

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🍓 REPORTING BUGS 🍓

for bug reports, use the issue tracker: <https://github.com/util-linux/util-linux/issues>.

bestie if something's broken, tell the tracker, not me 😭 i am simply the messenger 🧚

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🌸 AVAILABILITY 🌸

the fadvise command is part of the util-linux package, which can be downloaded from the Linux Kernel Archive: <https://www.kernel.org/pub/linux/utils/util-linux/>.

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and that's the whole page, you're so welcome 💖 this lil writeup came to you courtesy of util-linux 2.42.4, dated 2026-09-21 — periodt, go fadvise something 💅✨