pack_fread(3)

💖 pack_fread — the Allegro manual, but make it cute 💖

okay bestie, so this is a page from the Allegro manual (yes, the Allegro game programming library, the one that's been feeding game devs since forever 🎀), and it's all about pack_fread(3). she reads bytes. that's her whole thing. and she does it so well.

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✨ NAME ✨

pack_fread — reads n bytes from the stream. like, literally that. it's an Allegro game programming library function, and it is serving exactly one (1) purpose and slaying at it. 💅

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🌸 SYNOPSIS 🌸

#include <allegro.h>

long pack_fread(void *p, long n, PACKFILE *f);

look at her. three args. no notes. iconic. 👑

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🦋 DESCRIPTION 🦋

okay so here's the vibe: pack_fread reads n bytes out of the stream f, and it stashes them at the memory location that p is pointing at. that's it. that's the whole job. simple, effective, no drama. ✨

here's how it looks in the wild, for the girlies who need the visual:

unsigned char buf[256];
...
if (pack_fread(buf, 256, input_file) != 256)
   abort_on_error("Truncated input file!");

like, you ask for 256 bytes, you get 256 bytes, or you start panicking. main character energy on both sides of that if, fr fr. 💀

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🌈 RETURN VALUE 🌈

she returns the number of bytes actually read, and — listen — that number will be less than n if EOF got reached or if an error popped off. so if you asked for 256 and got 255, something is not okay and you should be paying attention. 👀

the error codes? they get stored in errno. so go check errno, bestie, she left you a note. 💌

ngl, comparing the return value against n is the entire safety net here. don't skip it. that's the vibe check and you will fail it if you ignore her.

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🫶 SEE ALSO 🫶

• pack_fopen(3) — open the stream first, obviously
• pack_fopen_chunk(3) — for the chunk girlies
• pack_feof(3) — check if you've hit the end
• expackf(3) — another sibling in the pack

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Allegro, version 4.4.3 — that's the source and the version, and this page is literally titled pack_fread(3) so you already knew. mwah. 😘✨ ily, go read some bytes responsibly. 🍓🧚💜