explain_mknod(3)

💖 explain_mknod(3) — Library Functions Manual 💖

okay bestie, buckle up, because this one is literally the glow-up your error messages have been waiting for. it's explain_mknod from the library functions manual, and it is giving ✨ helpful ✨.

---

🌸 NAME 🌸

explain_mknod — explain mknod(2) errors

✨ SYNOPSIS ✨

#include <libexplain/mknod.h>
const char *explain_mknod(const char *pathname, mode_t mode, dev_t dev);
const char *explain_errno_mknod(int errnum, const char *pathname, mode_t
mode, dev_t dev);
void explain_message_mknod(char *message, int message_size, const char
*pathname, mode_t mode, dev_t dev);
void explain_message_errno_mknod(char *message, int message_size, int
errnum, const char *pathname, mode_t mode, dev_t dev);

🦋 DESCRIPTION 🦋

so like, these functions are your little translators 🫶 — you use them to get actual explanations for errors that come back from the mknod(2) system call. not just vibes. real answers.

🎀 explain_mknod

const char *explain_mknod(const char *pathname, mode_t mode, dev_t dev);

the explain_mknod function is here to hand you an explanation of an error returned by the mknod(2) system call. the least the message will contain is the value of strerror(errno), but usually it does so much better and points at the underlying cause in more detail. main character energy honestly 👑

the errno global variable is the one used to grab the error value that's gonna get decoded.

• pathname — the original pathname, exactly as passed to the mknod(2) system call. no edits, no filters, no retouching 💅
• mode — the original mode, exactly as passed to the mknod(2) system call.
• dev — the original dev, exactly as passed to the mknod(2) system call.

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 will get overwritten by the next call to any libexplain function that shares this buffer, including other threads. so like, screenshot it, don't frame it 🫠

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. no cap.

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

if (mknod(pathname, mode, dev) < 0)
{
    fprintf(stderr, "%s\n", explain_mknod(pathname, mode, dev));
    exit(EXIT_FAILURE);
}

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

🌈 explain_errno_mknod

const char *explain_errno_mknod(int errnum, const char *pathname, mode_t
mode, dev_t dev);

the explain_errno_mknod function is used to obtain an explanation of an error returned by the mknod(2) 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.

• 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. so grab it early, bestie, it's slippery 🫣
• pathname — the original pathname, exactly as passed to the mknod(2) system call.
• mode — the original mode, exactly as passed to the mknod(2) system call.
• dev — the original dev, exactly as passed to the mknod(2) 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:

if (mknod(pathname, mode, dev) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_mknod(err, pathname,
    mode, dev));
    exit(EXIT_FAILURE);
}

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

💜 explain_message_mknod

void explain_message_mknod(char *message, int message_size, const char
*pathname, mode_t mode, dev_t dev);

the explain_message_mknod function is used to obtain an explanation of an error returned by the mknod(2) 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.

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 🥳
• message_size — the size in bytes of the location in which to store the returned message.
• pathname — the original pathname, exactly as passed to the mknod(2) system call.
• mode — the original mode, exactly as passed to the mknod(2) system call.
• dev — the original dev, exactly as passed to the mknod(2) system call.

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

if (mknod(pathname, mode, dev) < 0)
{
    char message[3000];
    explain_message_mknod(message, sizeof(message), pathname,
    mode, dev);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

🧚 explain_message_errno_mknod

void explain_message_errno_mknod(char *message, int message_size, int
errnum, const char *pathname, mode_t mode, dev_t dev);

the explain_message_errno_mknod function is used to obtain an explanation of an error returned by the mknod(2) 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.

• 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.
• pathname — the original pathname, exactly as passed to the mknod(2) system call.
• mode — the original mode, exactly as passed to the mknod(2) system call.
• dev — the original dev, exactly as passed to the mknod(2) system call.

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

if (mknod(pathname, mode, dev) < 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_mknod(message, sizeof(message), err,
    pathname, mode, dev);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

---

👀 SEE ALSO 👀

• mknod(2) — create a special or ordinary file
• explain_mknod_or_die(3) — create a special or ordinary file and report errors

💅 COPYRIGHT 💅

libexplain version 1.4 Copyright (C) 2009 Peter Miller

---

and that's the whole page, bestie, you ate it fr fr 💖 this was explain_mknod(3) from the Library Functions Manual, brought to you by libexplain version 1.4, copyright (C) 2009 Peter Miller — go forth and decode those mknod(2) errors like the icon you are ✨👑🦋