explain_pread_or_die(3)

💖 explain_pread_or_die(3) — Library Functions Manual, bestie edition 💖

okay so listen. this is a page from the Library Functions Manual, and it's all about explain_pread_or_die — which is literally just "read from a file at an offset, but if it goes wrong I will tell you exactly why and then dramatically exit". seek and read from a file descriptor and report errors, no cap. 🦋

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✨ NAME ✨

explain_pread_or_die — seek and read from a file descriptor and report errors

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🌸 SYNOPSIS 🌸

#include <libexplain/pread.h>
ssize_t explain_pread_or_die(int fildes, void *data, size_t data_size,
off_t offset);
ssize_t explain_pread_on_error(int fildes, void *data, size_t data_size,
off_t offset))

(and yes the second one really does have that extra ) at the end, i am not fixing it, that's just how it is, it's giving ✨character✨)

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💅 DESCRIPTION 💅

okay so there's two besties here and they're twins but with different personalities.

The explain_pread_or_die function is used to call the pread(2) system call. On failure an explanation will be printed to stderr, obtained from the explain_pread(3) function, and then the process terminates by calling exit(EXIT_FAILURE). so like. it doesn't do the "oops let me tell you gently" thing. it tells you, and then it dies. main character exit. 💀

The explain_pread_on_error function is used to call the pread(2) system call. On failure an explanation will be printed to stderr, obtained from the explain_pread(3) function, but still returns to the caller. so this one spills the tea and then stays in the group chat. 🫶

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🎀 the arguments 🎀

• fildes — The fildes, exactly as to be passed to the pread(2) system call.
• data — The data, exactly as to be passed to the pread(2) system call.
• data_size — The data_size, exactly as to be passed to the pread(2) system call.
• offset — The offset, exactly as to be passed to the pread(2) system call.

like, "exactly as to be passed to the pread(2) system call" is the whole vibe of this section. no extra seasoning. just straight through, untouched, periodt. 💜

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🔥 RETURN VALUE 🔥

The explain_pread_or_die function only returns on success, see pread(2) for more information. On failure, prints an explanation and exits, it does not return. so if you're holding your breath waiting for it to come back with an error code? bestie. it's not coming back. 😭

The explain_pread_on_error function always returns the value return by the wrapped pread(2) system call.

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🌈 EXAMPLE 🌈

The explain_pread_or_die function is intended to be used in a fashion similar to the following example:

ssize_t result = explain_pread_or_die(fildes, data, data_size, offset);

look at that. one line. iconic. she does her job and she's out. 👑

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👑 SEE ALSO 👑

• pread(2) — read from a file descriptor at a given offset
• explain_pread(3) — explain pread(2) errors
• exit(2) — terminate the calling process

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💜 COPYRIGHT 💜

libexplain version 1.4 Copyright (C) 2009 Peter Miller

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and that's the whole page, bestie 💖 this was explain_pread_or_die(3) from the Library Functions Manual — libexplain version 1.4, Copyright (C) 2009 Peter Miller, slay ✨🧚💅