GFS_PIO_READ(3)

✨ GFS_PIO_READ ✨

okay bestie, welcome to the gfs_pio_read(3) page — this is part of the Gfarm crew, and it's literally just how you pull raw bytes out of a file. binary stream input, that's the whole vibe. 🦋

🌸 SYNOPSIS 🌸

first things first, you gotta include the header, no cap:

#include <gfarm/gfarm.h>

gfarm_error_t gfs_pio_read(GFS_File gf, void * buffer, int size,
                           int * np);

that's the whole signature, copy it exactly, don't freestyle it 💅

💖 DESCRIPTION 💖

so like, gfs_pio_read() tries to read up to size bytes from the file that gf is referencing, and it drops them into the buffer starting at buffer. then it writes the number of bytes it actually read to the address that np is pointing at. 🫶

and when you hit the end of the file? the number of bytes read is zero. that's your little "we're done here" signal, periodt. 🌈

👑 RETURN VALUES 👑

here's the vibe check on what comes back at you:

• GFARM_ERR_NO_ERROR — it worked, the function terminated successfully, we ate 💅✨
• GFARM_ERR_OPERATION_NOT_PERMITTED — gf isn't specifying a regular file. not it.
• GFARM_ERR_BAD_FILE_DESCRIPTOR — the file descriptor that gf gave you is either not valid, or it's not open for reading. 💀
• GFARM_ERR_NO_FILE_SYSTEM_NODE — there's no available file system node. nothing to work with, bestie 😭
• GFARM_ERR_NO_MEMORY — insufficient memory was available. the memory said no 🙈
• Others — some other error happened that isn't on this list. the reason gets shown to you by gfarm_error_string(3), so go check that out 🎀

🔥 SEE ALSO 🔥

• gfs_pio_create(3)
• gfs_pio_open(3)

and that's the page, bestie!! this iconic little number comes to you from the Gfarm era of 27 Jun 2010 (yes, it's been slaying since 2010, iykyk) 💜 stay hydrated, close your file descriptors, and remember: zero bytes read means end of file, not that you failed. mwah 🎀✨