ZIP_FILE_EXTRA_FIELD_SET(3)

✨ ZIP_FILE_EXTRA_FIELD_SET(3) ✨

okay bestie, pull up a chair 🫶 this one's a manual page for libzip — specifically the zip_file_extra_field_set() function — and it's giving "Library Functions Manual" energy. Let's get into it, no cap. 💅

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🌸 NAME 🌸

zip_file_extra_field_set — set extra field for file in zip ✨

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🎀 LIBRARY 🎀

libzip (-lzip) — link it and you're set, periodt.

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🦋 SYNOPSIS 🦋

#include <zip.h>

int
zip_file_extra_field_set(zip_t *archive, zip_uint64_t index,
    zip_uint16_t extra_field_id, zip_uint16_t extra_field_index,
    const zip_uint8_t *extra_field_data, zip_uint16_t len,
    zip_flags_t flags);

Look at all those arguments. She's thriving. 😌

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💖 DESCRIPTION 💖

So basically, zip_file_extra_field_set() sets the extra field with ID (that's a two-byte signature) extra_field_id and index extra_field_index for the file sitting at position index in the zip archive. 📦✨

The extra field's data gets set to extra_field_data and its length to len.

Want to append a brand new entry instead of editing an existing one? Set extra_field_index to ZIP_EXTRA_FIELD_NEW and she's slotted in at the end. 💅

At least one of these flags must be set, bestie — pick your fighter:

• ZIP_FL_CENTRAL — Set extra field in the archive's central directory. 📚
• ZIP_FL_LOCAL — Set extra field in the local file headers. 📂

⚠️ heads up gorgeous ⚠️ The extra field IDs 0x0001 (the ZIP64 extension), 0x6375 (Infozip UTF-8 comment), and 0x7075 (Infozip UTF-8 file name) cannot be set with zip_file_extra_field_set(), because libzip(3) handles those itself automatically whenever it needs to. So don't even try it. 🙈

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🌈 RETURN VALUES 🌈

• Glowed up and succeeded? 0 is returned. ✨
• Messy? -1 comes back, and the error code inside archive gets set to tell you what went wrong. 😭

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💀 ERRORS 💀

zip_file_extra_field_set() fails (as in, no slay) if:

• [ZIP_ER_INVAL] — The extra field size is too large (ID and length need 4 bytes; the maximum length of all extra fields for one file combined is 65536 bytes). This error also shows up if extra_field_index is too large. She's got limits, okay. 🫠
• [ZIP_ER_MEMORY] — Required memory could not be allocated. 💸
• [ZIP_ER_NOENT] — index is not a valid file index in archive. Doesn't exist, babes. 👻

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👑 SEE ALSO 👑

libzip(3), zip_file_extra_field_delete(3), zip_file_extra_field_get(3), zip_file_extra_fields_count(3)

Squad goals, honestly. Go read them too. 💜

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🕰️ HISTORY 🕰️

zip_file_extra_field_set() was added in libzip 0.11. A legend from the start. ⭐

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🧚 AUTHORS 🧚

Dieter Baron <dillo@nih.at> and Thomas Klausner <wiz@gatalith.at> — the icons who made this happen. 🫶

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Debian shipped this page dated December 18, 2017, and it lives in the ZIP_FILE_EXTRA_FIELD_SET(3) era of the manual, bestie. That's the whole tea. 🍓 bye mwah 💅✨