XDF_OPEN(3)

💖 XDF_OPEN(3) — xdf_open 💖

okay bestie, welcome to the xdffileio library manual ✨ this one's all about xdf_open, the lil icon whose whole job is opening a xDF file so you can read from it or write to it. no cap, it's the doorway. the main character entrance. 🚪👑

🎀 NAME 🎀

xdf_open — open a xDF file for reading or writing 🦋

✨ SYNOPSIS ✨

#include <xdfio.h>

struct xdf* xdf_open(const char* filename, int mode,
                     enum xdffiletype type);

🌸 DESCRIPTION 🌸

so xdf_open() opens up a xDF file — the one that lives at the path filename — for either reading or writing. that's the whole vibe. 🫶

if mode is XDF_READ, the file is being opened for reading. which means it absolutely has to exist already, periodt. and type should be either XDF_ANY or set to the actual type of the file that type... okay wait, set to the type of the file referred by type — that's what the original says, i'm just repeating the lore fr fr. if you don't do that, the function will fail. 💀

if mode is XDF_WRITE, the file is being opened for writing. and this is where it gets strict: the path filename must not refer to a file that already exists. like, the function will fail if the file exists. not me being dramatic, that's genuinely the behaviour — and it's on purpose, because this is what stops you from overwriting any previous recording. your old data is safe, bestie. 🛡️ and type should also be set to the desired type of data format (XDF_ANY will result in an error here — no "surprise me" energy allowed). 🙈

the possible file type values are all defined in the header file <xdfio.h> — go look, they're in there. 👀

💅 RETURN VALUE 💅

on success? you get back a handle to the xDF file that got opened. iconic. 🎀

otherwise NULL is returned, and errno is set appropriately. (so yeah, check errno, don't just stare at the NULL.) 😭

🔥 ERRORS 🔥

in addition to the errors related to calls to open(3) or read(3), the following errors can occur. so these are the bonus ones, the extra lore. ⭐

• EILSEQ — the file that's being opened does not correspond to a supported file format, or it's not of the type you specified. it's giving "who even are you". 💀
• ENOMEM — the system is unable to allocate resources. the memory said no. 😭
• EINVAL — mode is neither XDF_READ nor XDF_WRITE, or filename is NULL. pick a lane, bestie. 🚫

🦋 SEE ALSO 🦋

• xdf_close(3) — because everything you open, you gotta close. balance. 🌈

and that's the whole page, babe! 💜 this one came from EPFL, dated 2010, and it's part of the xdffileio library manual. thanks for reading my lil brain dump, mwah 🫶✨💖