explain_setpriority(3)

💖 explain_setpriority — Library Functions Manual 💖

okay bestie, sit down, hydrate, because we're about to talk about explain_setpriority(3) from libexplain and honestly? it's giving "your error messages deserve better." ✨

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🌸 NAME 🌸

explain_setpriority — explain setpriority(2) errors 🫶

✨ SYNOPSIS ✨

#include <libexplain/setpriority.h>
const char *explain_setpriority(int which, int who, int prio);
const char *explain_errno_setpriority(int errnum, int which, int who,
int prio);
void explain_message_setpriority(char *message, int message_size, int
which, int who, int prio);
void explain_message_errno_setpriority(char *message, int message_size,
int errnum, int which, int who, int prio);

🦋 DESCRIPTION 🦋

So like, these functions? They're your little translators. You use them to get explanations for errors that the setpriority(2) system call throws back at you. Instead of just a sad vague errno, you get the whole story. no cap. 💅

💜 explain_setpriority

const char *explain_setpriority(int which, int who, int prio);

The explain_setpriority function is here to hand you an explanation of an error returned by the setpriority(2) system call. The least the message will contain is the value of strerror(errno), but usually it will do much better and point at the underlying cause in more detail. she's thorough, okay? 👑

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

• which — the original which, exactly as passed to the setpriority(2) system call. no edits, no vibes-based interpretation.
• who — the original who, exactly as passed to the setpriority(2) system call.
• prio — the original prio, exactly as passed to the setpriority(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. bestie. please. 😭

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

if (setpriority(which, who, prio) < 0)
{
    fprintf(stderr, "%s\n", explain_setpriority(which, who,
    prio));
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_setpriority_or_die(3) function. 🎀

💖 explain_errno_setpriority

const char *explain_errno_setpriority(int errnum, int which, int who,
int prio);

The explain_errno_setpriority function is used to obtain an explanation of an error returned by the setpriority(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. keep that in mind, it's a whole thing.
• which — the original which, exactly as passed to the setpriority(2) system call.
• who — the original who, exactly as passed to the setpriority(2) system call.
• prio — the original prio, exactly as passed to the setpriority(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 (setpriority(which, who, prio) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_setpriority(err, which,
    who, prio));
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_setpriority_or_die(3) function. 🦋

🌈 explain_message_setpriority

void explain_message_setpriority(char *message, int message_size, int
which, int who, int prio);

The explain_message_setpriority function is used to obtain an explanation of an error returned by the setpriority(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. slay.
• message_size — the size in bytes of the location in which to store the returned message.
• which — the original which, exactly as passed to the setpriority(2) system call.
• who — the original who, exactly as passed to the setpriority(2) system call.
• prio — the original prio, exactly as passed to the setpriority(2) system call.

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

if (setpriority(which, who, prio) < 0)
{
    char message[3000];
    explain_message_setpriority(message, sizeof(message), which,
    who, prio);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_setpriority_or_die(3) function. 💅

🎀 explain_message_errno_setpriority

void explain_message_errno_setpriority(char *message, int message_size,
int errnum, int which, int who, int prio);

The explain_message_errno_setpriority function is used to obtain an explanation of an error returned by the setpriority(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. (again!! she's persistent!!)
• which — the original which, exactly as passed to the setpriority(2) system call.
• who — the original who, exactly as passed to the setpriority(2) system call.
• prio — the original prio, exactly as passed to the setpriority(2) system call.

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

if (setpriority(which, who, prio) < 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_setpriority(message, sizeof(message),
    err, which, who, prio);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_setpriority_or_die(3) function. ⭐

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👀 SEE ALSO 👀

• setpriority(2) — set program scheduling priority
• explain_setpriority_or_die(3) — set program scheduling priority and report errors

📜 COPYRIGHT 📜

• libexplain version 1.4
• Copyright (C) 2013 Peter Miller

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and that's the whole page, bestie 🧚💜 literally every flag, every argument, every buffer warning, all of it — nothing skipped, nothing made up, periodt. this was explain_setpriority(3) from libexplain version 1.4, © 2013 Peter Miller, and she ate. 💅✨🌸