explain_fdopendir(3)

💖 explain_fdopendir(3) 💖

okay bestie, so this is a page from the Library Functions Manual and it's all about the explain_fdopendir crew — the little functions that turn your fdopendir(3) oopsies into actual words you can read. no cap, they're so useful. 🦋

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✨ NAME ✨

explain_fdopendir — explain fdopendir(3) errors 💅

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✨ SYNOPSIS ✨

#include <libexplain/fdopendir.h>
const char *explain_fdopendir(int fildes);
const char *explain_errno_fdopendir(int errnum, int fildes);
void explain_message_fdopendir(char *message, int message_size, int fildes);
void explain_message_errno_fdopendir(char *message, int message_size, int errnum, int fildes);

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✨ DESCRIPTION ✨

so like, these functions are your go-to besties when you wanna get actual explanations for errors that come back from the fdopendir(3) system call. they don't just shrug at you — they tell you what's up. 🫶

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🌸 explain_fdopendir 🌸

const char *explain_fdopendir(int fildes);

the explain_fdopendir function is literally the one you call to get an explanation of an error returned by the fdopendir(3) system call. the least the message is gonna contain is the value of strerror(errno), but ngl it usually does way better than that and points at the underlying cause in more detail. it's giving detective energy. 🔍

the errno global variable gets used to grab the error value that needs decoding. periodt.

• fildes — the original fildes, exactly as passed to the fdopendir(3) system call. don't get cute with it, pass it as-is. 🙈

Returns: the message explaining the error. this message buffer is shared by all libexplain functions that don't supply a buffer in their argument list. it's gonna get overwritten by the next call to any libexplain function that shares this buffer — including calls from other threads. so yeah. 😭

Note: this function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library do too. heads up, bestie.

Example: this function is meant to be used in a fashion similar to the following example:

DIR *result = fdopendir(fildes);
if (!result)
{
    fprintf(stderr, "%s\n", explain_fdopendir(fildes));
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_fdopendir_or_die(3) function. iconic, honestly. ✨

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🌸 explain_errno_fdopendir 🌸

const char *explain_errno_fdopendir(int errnum, int fildes);

the explain_errno_fdopendir function is used to obtain an explanation of an error returned by the fdopendir(3) system call. the least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail. she ate. 💅

• errnum — the error value to be decoded, usually grabbed from the errno global variable right before this function is called. this is necessary if you need to call any code between the system call being explained and this function, because so many libc functions will alter the value of errno. sneaky little things. 💀
• fildes — the original fildes, exactly as passed to the fdopendir(3) system call.

Returns: the message explaining the error. this message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. this will be overwritten by the next call to any libexplain function which shares this buffer, including other threads.

Note: this function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library.

Example: this function is intended to be used in a fashion similar to the following example:

DIR *result = fdopendir(fildes);
if (!result)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_fdopendir(err, fildes));
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_fdopendir_or_die(3) function.

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🌸 explain_message_fdopendir 🌸

void explain_message_fdopendir(char *message, int message_size, int fildes);

the explain_message_fdopendir function is used to obtain an explanation of an error returned by the fdopendir(3) system call. the least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail. main character energy fr fr. 👑

the errno global variable will be used to obtain the error value to be decoded.

• message — the location in which to store the returned message. if a suitable message return buffer is supplied, this function is thread safe. slay. 🎀
• message_size — the size in bytes of the location in which to store the returned message.
• fildes — the original fildes, exactly as passed to the fdopendir(3) system call.

Example: this function is intended to be used in a fashion similar to the following example:

DIR *result = fdopendir(fildes);
if (!result)
{
    char message[3000];
    explain_message_fdopendir(message, sizeof(message), fildes);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_fdopendir_or_die(3) function.

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🌸 explain_message_errno_fdopendir 🌸

void explain_message_errno_fdopendir(char *message, int message_size, int errnum, int fildes);

the explain_message_errno_fdopendir function is used to obtain an explanation of an error returned by the fdopendir(3) system call. the least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail. obsessed. 🌈

• message — the location in which to store the returned message. if a suitable message return buffer is supplied, this function is thread safe.
• message_size — the size in bytes of the location in which to store the returned message.
• errnum — the error value to be decoded, usually obtained from the errno global variable just before this function is called. this is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno.
• fildes — the original fildes, exactly as passed to the fdopendir(3) system call.

Example: this function is intended to be used in a fashion similar to the following example:

DIR *result = fdopendir(fildes);
if (!result)
{
    int err = errno;
    char message[3000];
    explain_message_errno_fdopendir(message, sizeof(message), err, fildes);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_fdopendir_or_die(3) function.

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✨ SEE ALSO ✨

• fdopendir(3) — open a directory 🦋
• explain_fdopendir_or_die(3) — open a directory and report errors 🔥

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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 lil' manual page came to you from libexplain version 1.4, with the copyright held by Peter Miller, 2009. go forth and debug like the icon you are. ✨💅🫶