explain_putw(3)

✨ NAME ✨

explain_putw — bestie, this is the page that explains all the putw(3) errors 💅

Like, this is the explain_putw(3) manual, and it's literally here to translate your cryptic little putw(3) failures into words you can actually read 🫶

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🌸 SYNOPSIS 🌸

#include <libexplain/putw.h>
const char *explain_putw(int value, FILE *fp);
const char *explain_errno_putw(int errnum, int value, FILE *fp);
void explain_message_putw(char *message, int message_size, int value,
FILE *fp);
void explain_message_errno_putw(char *message, int message_size, int
errnum, int value, FILE *fp);

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🦋 DESCRIPTION 🦋

okay so. These functions? They exist so you can get actual explanations for errors that come back from the putw(3) system call. No more staring at a number like it personally wronged you 😭

💜 explain_putw

const char *explain_putw(int value, FILE *fp);

The explain_putw function is how you get an explanation of an error that putw(3) handed back to you. The absolute bare minimum the message will contain is the value of strerror(errno), but ngl usually it does way better than that and points at the actual underlying cause in more detail. iconic behavior honestly.

The errno global variable is what gets used to grab the error value that's gonna be decoded. fr fr.

• value — the original value, exactly as passed to the putw(3) system call. don't touch it, don't rename it, it's a whole vibe.
• fp — the original fp, exactly as passed to the putw(3) system call. same energy.

Returns:

The message explaining the error. Heads up bestie: this message buffer is shared by all libexplain functions that don't supply a buffer in their argument list. Which means it gets overwritten by the next call to any libexplain function that shares this buffer — including calls from 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 too. no cap.

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

if (putw(value, fp) < 0)
{
    fprintf(stderr, "%s\n", explain_putw(value, fp));
    exit(EXIT_FAILURE);
}

The above code example is available pre‐packaged as the explain_putw_or_die(3) function. so you don't even have to write it yourself, slay 🎀

🌈 explain_errno_putw

const char *explain_errno_putw(int errnum, int value, FILE *fp);

The explain_errno_putw function is used to obtain an explanation of an error returned by the putw(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. ✨

• errnum — the error value to be decoded, usually grabbed from the errno global variable right before this function gets 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 really, they're sneaky like that 🙈
• value — the original value, exactly as passed to the putw(3) system call.
• fp — the original fp, exactly as passed to the putw(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:

if (putw(value, fp) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_putw(err, value, fp));
    exit(EXIT_FAILURE);
}

The above code example is available pre‐packaged as the explain_putw_or_die(3) function. 💖

🧚 explain_message_putw

void explain_message_putw(char *message, int message_size, int value,
FILE *fp);

The explain_message_putw function is used to obtain an explanation of an error returned by the putw(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.

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 👑
• message_size — the size in bytes of the location in which to store the returned message.
• value — the original value, exactly as passed to the putw(3) system call.
• fp — the original fp, exactly as passed to the putw(3) system call.

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

if (putw(value, fp) < 0)
{
    char message[3000];
    explain_message_putw(message, sizeof(message), value, fp);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre‐packaged as the explain_putw_or_die(3) function. 🍓

⭐ explain_message_errno_putw

void explain_message_errno_putw(char *message, int message_size, int
errnum, int value, FILE *fp);

The explain_message_errno_putw function is used to obtain an explanation of an error returned by the putw(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.

• 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.
• value — the original value, exactly as passed to the putw(3) system call.
• fp — the original fp, exactly as passed to the putw(3) system call.

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

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

The above code example is available pre‐packaged as the explain_putw_or_die(3) function. 🔥

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👑 SEE ALSO 👑

• putw(3) — output a word (int)
• explain_putw_or_die(3) — output a word (int) and report errors

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💅 COPYRIGHT 💅

• libexplain version 1.4
• Copyright (C) 2010 Peter Miller

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okay that's the whole page, bestie, you're officially smarter than everyone who just reads errno raw 💜

This was explain_putw(3) from libexplain version 1.4, copyright Copyright (C) 2010 Peter Miller. mwah, go forth and decode your errors 🌈🫶