explain_uname(3)

💖 explain_uname(3) — Library Functions Manual 💖

okay bestie, sit DOWN, because we're about to make uname(2) errors make sense 💅 this is a libexplain page, and it's giving "I will tell you exactly why your syscall flopped" energy ✨

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🌸 NAME 🌸

explain_uname — the way it explains uname(2) errors, no cap 🫶

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✨ SYNOPSIS ✨

#include <libexplain/uname.h>
const char *explain_uname(struct utsname *data);
const char *explain_errno_uname(int errnum, struct utsname *data);
void explain_message_uname(char *message, int message_size, struct
utsname *data);
void explain_message_errno_uname(char *message, int message_size, int
errnum, struct utsname *data);

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🦋 DESCRIPTION 🦋

so these functions?? they're the ones you call when uname(2) said "no 💀" and you need to know why. They hand you explanations for errors returned by the uname(2) system call. iconic behavior, honestly 👑

💜 explain_uname

const char *explain_uname(struct utsname *data);

the explain_uname function is your girl for getting an explanation of an error that uname(2) returned. the least the message will contain is the value of strerror(errno), but usually it does soooo much better than that and points at the actual underlying cause in more detail 🔍

the errno global variable is what gets used to obtain the error value to be decoded.

• data — the original data, exactly as passed to the uname(2) system call. don't get cute with it, pass it as-is bestie 🙈

Returns:

the message explaining the error. and here's the tea ☕ — 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 screenshot it, copy it, do whatever, just don't hold onto it 💀

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

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

if (uname(data) < 0)
{
    fprintf(stderr, "%s\n", explain_uname(data));
    exit(EXIT_FAILURE);
}

and the above code example is available pre-packaged as the explain_uname_or_die(3) function 🎀

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💅 explain_errno_uname

const char *explain_errno_uname(int errnum, struct utsname *data);

the explain_errno_uname function is used to obtain an explanation of an error returned by the uname(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. yes, they will absolutely snatch your errno out from under you, so save it first 🙈
• data — the original data, exactly as passed to the uname(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 (uname(data) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_uname(err, data));
    exit(EXIT_FAILURE);
}

the above code example is available pre-packaged as the explain_uname_or_die(3) function 🫶

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🎀 explain_message_uname

void explain_message_uname(char *message, int message_size, struct
utsname *data);

the explain_message_uname function is used to obtain an explanation of an error returned by the uname(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. look at her, being all safe and considerate 👑
• message_size — the size in bytes of the location in which to store the returned message.
• data — the original data, exactly as passed to the uname(2) system call.

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

if (uname(data) < 0)
{
    char message[3000];
    explain_message_uname(message, sizeof(message), data);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

the above code example is available pre-packaged as the explain_uname_or_die(3) function 💖

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🧚 explain_message_errno_uname

void explain_message_errno_uname(char *message, int message_size, int
errnum, struct utsname *data);

the explain_message_errno_uname function is used to obtain an explanation of an error returned by the uname(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. she ate 💅
• 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. save it EARLY bestie, they're coming for it 😭
• data — the original data, exactly as passed to the uname(2) system call.

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

if (uname(data) < 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_uname(message, sizeof(message), err,
    data);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

the above code example is available pre-packaged as the explain_uname_or_die(3) function 🍓

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🌈 SEE ALSO 🌈

• uname(2) — get name and information about current kernel
• explain_uname_or_die(3) — get name and information about current kernel and report errors

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👑 COPYRIGHT 👑

libexplain version 1.4 Copyright (C) 2013 Peter Miller

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and that's the whole page, bestie 🫶 go forth and explain your uname(2) errors like the main character you are. mwah 💋

libexplain version 1.4, Copyright (C) 2013 Peter Miller — the origin story, preserved forever, no edits, we respect the elders 💜