vrb_read_min(3)

💅 vrb_read_min(3) — from the VRB Programmer's Manual, bestie

okay so picture this: it's vrb_read_min(3), she's a real one, and she lives in the VRB Programmer's Manual. that's the whole vibe. let's get into it 🫶

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✨ NAME ✨

vrb_read_min — reading a minimum of data into a VRB. not vibes, actual bytes. minimum effort is NOT the point here for once 💀

📚 LIBRARY 📚

-lvrb

link it and go, bestie 🌸

🎀 SYNOPSIS 🎀

#include <vrb.h>

size_t vrb_read_min(vrb_p vrb, int fd, size_t maxsize, size_t minsize);

🔥 DESCRIPTION 🔥

okay so here's the tea ☕ — vrb_read_min reads a minimum amount of data from a specified open file descriptor, using read(2), into the specified virtual ring buffer. she keeps going until:

• the specified maximum length has been read,
• the buffer is full,
• end-of-file hits, or
• an error is returned (this includes EAGAIN or EWOULDBLOCK for a non-blocking descriptor 😭).

and here's the iconic part: if there is insufficient space in the buffer to read the minimum amount, then read(2) will not be called at all. she simply does not show up. main character boundary-setting energy 👑

🌈 ARGUMENTS 🌈

• vrb_p vrb — specifies which virtual ring buffer. like, which one, bestie.
• int fd — specifies the open file descriptor to read from 🍓
• size_t maxsize — specifies the maximum length to read, or ~0 for unlimited. go off, no cap ✨
• size_t minsize — specifies the minimum length to read. the bare minimum, literally.

💖 RETURN VALUE 💖

size_t

• if successful, the actual length of data read into the buffer is returned 💅
• if the minimum amount of space was not available to read into, 0 is returned.
• if end-of-file occurs, the return value is ~0 and errno is 0.
• if an error occurs from read(2), the return value is ~0 and errno is set by read(2).

🦋 ERRORS 🦋

if an error is returned, then errno will have one of the following values:

• 0 — an end-of-file has occurred. ⚠️ note that this is a different way of returning an end-of-file condition than read(2) uses. yes really, she does it her own way 🙈
• EINVAL — an invalid virtual ring buffer pointer was specified. wrong pointer, wrong girl 💀

👑 SEE ALSO 👑

vrb(3), vrb_capacity(3), vrb_data_len(3), vrb_data_ptr(3), vrb_destroy(3), vrb_get(3), vrb_get_min(3), vrb_give(3), vrb_init(3), vrb_init_opt(3), vrb_is_empty(3), vrb_is_full(3), vrb_is_not_empty(3), vrb_is_not_full(3), vrb_move(3), vrb_new(3), vrb_new_opt(3), vrb_put(3), vrb_put_all(3), vrb_read(3), vrb_resize(3), vrb_space_len(3), vrb_space_ptr(3), vrb_take(3), vrb_uninit(3), vrb_write(3), vrb_write_min(3), read(2)

the whole friend group, fr fr 🧚

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and that's the page, bestie — brought to you by the legend herself, vrb, dated 2002-09-30. she's been iconic since day one and she's not stopping 💜⭐