zzip_disk_fopen(3)

💖 zzip_disk_fopen — the zziplib function list, but make it make sense ✨

okay bestie, this is a page from the zziplib manual — specifically the zzip_disk_fopen(3) one — and it's all about opening a file part that's wrapped up inside a (mmapped) zip archive 🫶. buckle up, it's giving very niche but very iconic.

---

🌸 NAME 🌸

zzip_disk_fopen, zzip_disk_entry_fopen, zzip_disk_fread, zzip_disk_fclose, zzip_disk_feof — opening a file part wrapped within a (mmapped) zip archive. that's the whole squad, they roll together 💅

---

✨ SYNOPSIS ✨

first thing first, you gotta bring in the header:

#include <zzip/mmapped.h>

then here's the whole friend group, signature by signature:

zzip__new__ ZZIP_DISK_FILE *
zzip_disk_fopen(ZZIP_DISK * disk, char *filename)

zzip__new__ ZZIP_DISK_FILE *
zzip_disk_entry_fopen(ZZIP_DISK * disk, ZZIP_DISK_ENTRY * entry)

zzip_size_t
zzip_disk_fread(void *ptr, zzip_size_t sized, zzip_size_t nmemb,
                ZZIP_DISK_FILE * file)

int
zzip_disk_fclose(ZZIP_DISK_FILE * file)

int
zzip_disk_feof(ZZIP_DISK_FILE * file)

no cap, that's exactly it, character for character 💜

---

🦋 DESCRIPTION 🦋

okay so, zzip_disk_fopen — she opens a file that you find by name. the way she does it is she does a search into the zip central directory with zzip_disk_findfile, and then whatever is found first gets handed straight to zzip_disk_entry_fopen. like a little handoff, very team player of her 🎀

⚠️ zzip_disk_fopen may return null on errors (errno). so check that pointer, bestie, don't just vibe forward assuming it worked 😭

the ZZIP_DISK_FILE* is rather simple — lowkey unbothered — it just encapsulates the arguments that were given to the zzip_disk_entry_fopen function, plus a zlib deflate buffer. and note this: the ZZIP_DISK pointer already contains the full mmapped file area of a zip disk, so open()ing a file part within that area is basically just a lookup of its bounds and encoding. that info gets memorized on the ZZIP_DISK_FILE, so that subsequent _read() operations will be able to get the next data portion, or return an eof condition for that file part wrapped in the zip archive. she's organized, she remembers things, main character energy fr fr 👑

zzip_disk_entry_fopen may return null on errors too, and the errno situation is errno = ENOMEM|EBADMSG. so like, either out of memory or bad message — pick your struggle 🙈

zzip_disk_fread reads more bytes into the output buffer specified as arguments. the return value is null on eof or error, and here's the annoying part: the stdio-like interface can not distinguish between these, so you need to check with zzip_disk_feof to tell the difference. it's giving ambiguous, and not in a fun way 💀

zzip_disk_fclose releases any zlib decoder info needed for decompression, and then dumps the ZZIP_DISK_FILE*. clean exit, we love a tidy queen ✨

and zzip_disk_fclose always returns 0. always. no drama, no surprises, periodt.

zzip_disk_feof is the one who lets you distinguish an error from an eof condition. actually — and this is kind of a vibe — if we found an error but we did already reach eof, then we just keep on saying that it was an eof, so the app can just continue. like, we're being chill about it so nothing crashes on you 🌈

and zzip_disk_feof returns EOF in case, and 0 when not at the end of file. simple as that 💅

---

🫶 AUTHOR 🫶

Guido Draheim <guidod@gmx.de> — thank you king, we appreciate you 🌟

---

💜 COPYRIGHT 💜

Copyright (c)Guido Draheim, use under copyleft (LGPL,MPL). so like, share the love, keep it copyleft 🎀

---

and that's the whole page, bestie!! this was the zzip_disk_fopen(3) page from zziplib 0.13.72 — go forth and open your zip parts responsibly, mwah 💖🧚‍♀️