explain_getgroups(3)

💖 explain_getgroups(3) 💖

okay so bestie, this is a page from the Library Functions Manual — it's explain_getgroups(3), and it's literally your new fave thing if you've ever stared at a getgroups(2) error like "what do you WANT from me 😭". Buckle up, we're decoding errors together 🫶

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✨ NAME ✨

explain_getgroups — explain getgroups(2) errors. that's it, that's the job 💅

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✨ SYNOPSIS ✨

#include <libexplain/getgroups.h>
const char *explain_getgroups(int data_size, gid_t *data);
const char *explain_errno_getgroups(int errnum, int data_size, gid_t *data);
void explain_message_getgroups(char *message, int message_size, int data_size, gid_t *data);
void explain_message_errno_getgroups(char *message, int message_size, int errnum, int data_size, gid_t *data);

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✨ DESCRIPTION ✨

These functions may be used to obtain explanations for errors returned by the getgroups(2) system call. no cap, that's the whole point of them 🌸

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🎀 explain_getgroups

const char *explain_getgroups(int data_size, gid_t *data);

The explain_getgroups function is used to obtain an explanation of an error returned by the getgroups(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. it's giving overachiever ✨

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

• data_size — The original data_size, exactly as passed to the getgroups(2) system call.
• data — The original data, exactly as passed to the getgroups(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. so like, don't get attached to it 💀

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 (getgroups(data_size, data) < 0)
{
    fprintf(stderr, "%s\n", explain_getgroups(data_size, data));
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_getgroups_or_die(3) function. iconic behavior honestly 👑

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🎀 explain_errno_getgroups

const char *explain_errno_getgroups(int errnum, int data_size, gid_t *data);

The explain_errno_getgroups function is used to obtain an explanation of an error returned by the getgroups(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. main character energy fr fr 💖

• 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. lowkey sneaky of them 😤
• data_size — The original data_size, exactly as passed to the getgroups(2) system call.
• data — The original data, exactly as passed to the getgroups(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 (getgroups(data_size, data) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_getgroups(err, data_size, data));
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_getgroups_or_die(3) function. ate that 🍓

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🎀 explain_message_getgroups

void explain_message_getgroups(char *message, int message_size, int data_size, gid_t *data);

The explain_message_getgroups function is used to obtain an explanation of an error returned by the getgroups(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. obsessed 🦋

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 go, so responsible 💅
• message_size — The size in bytes of the location in which to store the returned message.
• data_size — The original data_size, exactly as passed to the getgroups(2) system call.
• data — The original data, exactly as passed to the getgroups(2) system call.

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

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

The above code example is available pre-packaged as the explain_getgroups_or_die(3) function. periodt ✨

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🎀 explain_message_errno_getgroups

void explain_message_errno_getgroups(char *message, int message_size, int errnum, int data_size, gid_t *data);

The explain_message_errno_getgroups function is used to obtain an explanation of an error returned by the getgroups(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 way she explains things 😭💜

• 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.
• data_size — The original data_size, exactly as passed to the getgroups(2) system call.
• data — The original data, exactly as passed to the getgroups(2) system call.

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

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

The above code example is available pre-packaged as the explain_getgroups_or_die(3) function. slay 🧚

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🌈 SEE ALSO 🌈

• getgroups(2) — get/set list of supplementary group IDs
• explain_getgroups_or_die(3) — get/set list of supplementary group IDs 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 💖 go forth and explain your getgroups(2) errors with your whole chest. this was explain_getgroups(3) from the Library Functions Manual — libexplain version 1.4, Copyright (C) 2009 Peter Miller — mwah, bye 🎀✨🫶