vrb_read(3)

✨ vrb_read(3) — the VRB Programmer's Manual, section 3, bestie ✨

okay so real talk, this one is from the VRB Programmer's Manual and it's genuinely one of my faves because it does exactly one thing and it does it slayfully 💅

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🌸 NAME 🌸

vrb_read — read data into a VRB. that's it. that's the whole job. iconic.

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🎀 LIBRARY 🎀

-lvrb

(link against it or you get nothing, fr fr 🔥)

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✨ SYNOPSIS ✨

#include <vrb.h>

size_t vrb_read(vrb_p vrb, int fd, size_t size);

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🦋 DESCRIPTION 🦋

okay so here's the vibe: vrb_read reads data from a specified open file descriptor — using read(2) under the hood, ngl — straight into the specified virtual ring buffer. 💫

and it keeps going until any of these happen:

• the specified maximum length has been read,
• the buffer is full,
• end-of-file hits,
• or an error comes back (and yes, that includes EAGAIN or EWOULDBLOCK if your descriptor is non-blocking 👀).

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🌈 ARGUMENTS 🌈

• vrb_p vrb — specifies which virtual ring buffer. like, which one. this one. the one you mean. 🫶
• int fd — specifies the open file descriptor to read from 🔥
• size_t size — specifies the maximum length to read, or ~0 for unlimited. go big or go home, yk? 💜

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👑 RETURN VALUE 👑

returns size_t.

• if it's successful, you get the actual length of data read into the buffer back. slay. ✨
• 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).

⚠️ bestie please note: this is a different way of returning an end-of-file condition than read(2) uses. that's not a bug, that's just the house style. don't come for me 😭

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💀 ERRORS 💀

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

• 0 — an end-of-file has occurred. and again, note that this is a different way of returning an end-of-file condition than read(2) uses. i said what i said 🙈
• EINVAL — an invalid virtual ring buffer pointer was specified. you handed it a fake vrb, it's not gonna pretend to like it 💅

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🧚 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_min(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, basically 🫶 go say hi)

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and that's the page!! 🎀 authored under vrb, dated 2002-09-30, from the VRB Programmer's Manual — vintage but still eating, no cap 🍓✨