ZIP_SOURCE_SEEK_COMPUTE_OFFSET(3)

✨ ZIP_SOURCE_SEEK_COMPUTE_OFFSET ✨

okay so bestie, welcome to libzip's little helper function, aka the vibe-checker for seek math 💅 this page lives in section 3 of the manual (library functions, iykyk) and it's about validating arguments and computing an offset. that's it. that's the whole job. and she does it flawlessly. 🎀

Also she lives in libzip — you link against her with -lzip. 🦋

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🌸 SYNOPSIS 🌸

#include <zip.h>

zip_int64_t
zip_source_seek_compute_offset(zip_uint64_t offset, zip_uint64_t length,
    void *data, zip_uint64_t data_length, zip_error_t *error);

that's the whole signature, no cap. five arguments, one zip_int64_t coming back at you. 💖

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✨ DESCRIPTION ✨

okay so here's the tea ☕ — you use this function to compute the offset for a ZIP_SOURCE_SEEK or a ZIP_SOURCE_SEEK_WRITE command. like, that's literally her whole purpose in life and honestly? iconic. 👑

let's break down the cast of characters:

• data and data_length are the arguments to the source callback. so like, the raw stuff your callback got handed. 🫶
• offset is the current offset. where you're at right now, bestie.
• length is the length of the source data — OR, if you're doing ZIP_SOURCE_SEEK_WRITE, it's the amount of data written. two moods, one parameter. she contains multitudes. 💜

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🌈 RETURN VALUES 🌈

• on success? she returns the new offset. slay. ✨
• on error? she returns -1 and sets error. 😭 not the glow-down but okay, at least she tells you what went wrong.

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💀 ERRORS 💀

zip_source_seek_compute_offset() fails if:

• [ZIP_ER_INVAL] — one of the arguments is invalid, OR the seek would place the offset outside the data. basically: bad input, or you tried to seek somewhere that doesn't exist. the audacity. 🙈

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👀 SEE ALSO 👀

• zip_source_function(3)

go read that one too, bestie, they're a package deal. 🎀

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🕰️ HISTORY 🕰️

zip_source_seek_compute_offset() was added in libzip 1.0. a true original. a founding mother. 👑

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🫶 AUTHORS 🫶

• Dieter Baron <dillo@nih.at>
• Thomas Klausner <wiz@gatalith.at>

we stan both of them fr fr. 💖

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heads up bestie: this page came from Debian, dated December 18. that's the source and the date, so now you know where she came from. 🦋 mwah, go compute some offsets, you've got this. 💅✨