explain_fseek_or_die(3)

💖 explain_fseek_or_die — bestie edition 💖

okay so this is a page from the Library Functions Manual, and it's all about explain_fseek_or_die(3). yes the name is a whole sentence, we love a descriptive queen. let's get into it 🫶

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✨ NAME ✨

explain_fseek_or_die — reposition a stream and report errors. that's it, that's the job. no cap. 💅

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🌸 SYNOPSIS 🌸

#include <libexplain/fseek.h>
void explain_fseek_or_die(FILE *fp, long offset, int whence);
int explain_fseek_on_error(FILE *fp, long offset, int whence);

look at those two little function besties. one of them is dramatic and the other one is chill. we'll get to that. 🦋

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👑 DESCRIPTION 👑

so. there are two functions here and they're like the same person with two different coping mechanisms.

explain_fseek_or_die is the one that calls the fseek(3) system call, and if things go wrong? it prints an explanation to stderr (grabbed from the explain_fseek(3) function, she's the one who does the talking) and then the process literally terminates by calling exit(EXIT_FAILURE). it's giving main character exit. it does not come back. periodt. 💀

explain_fseek_on_error is the calmer sibling. it also calls the fseek(3) system call, and on failure it also prints an explanation to stderr — again, obtained from the explain_fseek(3) function — but then it still returns to the caller. no exit, no drama, just vibes and information. 🌈

the arguments, bestie 🎀

• fp — the fp, exactly as to be passed to the fseek(3) system call. like, no edits, no remixes, pass it through as-is. ✨
• offset — the offset, exactly as to be passed to the fseek(3) system call. same energy. same rule. 💜
• whence — the whence, exactly as to be passed to the fseek(3) system call. you already know the pattern by now. 🧚

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🦋 RETURN VALUE 🦋

• explain_fseek_or_die only returns on success — and if you want the details on that, go read fseek(3), she has the lore. on failure it prints an explanation and exits. it does not return. not even a little. 😭
• explain_fseek_on_error always returns the value returned by the wrapped fseek(3) system call. always. every single time. reliable icon. 👑

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🔥 EXAMPLE 🔥

the explain_fseek_or_die function is intended to be used in a fashion similar to the following example:

explain_fseek_or_die(fp, offset, whence);

that's the whole thing. so simple. so clean. ate. 💅

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🌟 SEE ALSO 🌟

• fseek(3) — reposition a stream
• explain_fseek(3) — explain fseek(3) errors
• exit(2) — terminate the calling process

go read them, they're all part of the same friend group. iykyk. 🫶

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💜 COPYRIGHT 💜

this is libexplain version 1.4, and the copyright belongs to Copyright (C) 2010 Peter Miller. respect the author, she fed us. 🍓

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and that's the whole page bestie!! mwah, thanks for reading, stay hydrated, and remember: one of these functions will absolutely end your process and the other one won't. choose wisely. 💖✨🎀🦋🌸