explain_setbuf(3)

💖 NAME 💖

okay so bestie, welcome to explain_setbuf — this is the page that explains how to get explanations for errors coming back from setbuf(3). it's giving "translator for your error codes," periodt.

This whole thing lives in the libexplain library's manual, section 3 (that's the library functions manual, iykyk).

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✨ SYNOPSIS ✨

like, here's the vibe check on what you're actually calling:

#include <libexplain/setbuf.h>
const char *explain_setbuf(FILE *fp, char *data);
const char *explain_errno_setbuf(int errnum, FILE *fp, char *data);
void explain_message_setbuf(char *message, int message_size, FILE *fp,
       char *data);
void explain_message_errno_setbuf(char *message, int message_size, int
       errnum, FILE *fp, char *data);

four functions, four ways to be emotionally supported by your own code 🫶

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🌸 DESCRIPTION 🌸

okay so the whole point of these four besties is: you can use them to obtain explanations for errors returned by the setbuf(3) system call. that's it, that's the thesis. they're the friend who reads the cryptic text message and tells you what it actually means. 💅

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🎀 explain_setbuf

const char *explain_setbuf(FILE *fp, char *data);

The explain_setbuf function is used to obtain an explanation of an error returned by the setbuf(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. lowkey overachieving, we love that.

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

• fp — The original fp, exactly as passed to the setbuf(3) system call.
• data — The original data, exactly as passed to the setbuf(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. no cap, this is a real hazard — one thread's message is another thread's chaos. 💀

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

errno = 0;
void result = setbuf(fp, data);
if (result < 0 && errno != 0)
{
    fprintf(stderr, "%s\n", explain_setbuf(fp, data));
    exit(EXIT_FAILURE);
}

The above code example is available pre‐packaged as the explain_setbuf_or_die(3) function. it's literally the same thing but already wrapped up for you, iconic. 👑

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🦋 explain_errno_setbuf

const char *explain_errno_setbuf(int errnum, FILE *fp, char *data);

The explain_errno_setbuf function is used to obtain an explanation of an error returned by the setbuf(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. same energy as before, just with the error number handed to it directly.

• 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 like, grab it immediately, bestie, don't let it get away. 🏃‍♀️
• fp — The original fp, exactly as passed to the setbuf(3) system call.
• data — The original data, exactly as passed to the setbuf(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:

errno = 0;
void result = setbuf(fp, data);
if (result < 0 && errno != 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_setbuf(err, fp, data));
    exit(EXIT_FAILURE);
}

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

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🌈 explain_message_setbuf

void explain_message_setbuf(char *message, int message_size, FILE *fp,
       char *data);

The explain_message_setbuf function is used to obtain an explanation of an error returned by the setbuf(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. finally, the thread-safe one arrives and she ate. 💅✨
• message_size — The size in bytes of the location in which to store the returned message.
• fp — The original fp, exactly as passed to the setbuf(3) system call.
• data — The original data, exactly as passed to the setbuf(3) system call.

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

errno = 0;
void result = setbuf(fp, data);
if (result < 0 && errno != 0)
{
    char message[3000];
    explain_message_setbuf(message, sizeof(message), fp, data);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

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🧚 explain_message_errno_setbuf

void explain_message_errno_setbuf(char *message, int message_size, int
       errnum, FILE *fp, char *data);

The explain_message_errno_setbuf function is used to obtain an explanation of an error returned by the setbuf(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 final form, the ultimate crossover episode. 🌟

• 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.
• fp — The original fp, exactly as passed to the setbuf(3) system call.
• data — The original data, exactly as passed to the setbuf(3) system call.

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

errno = 0;
void result = setbuf(fp, data);
if (result < 0 && errno != 0)
{
    int err = errno;
    char message[3000];
    explain_message_errno_setbuf(message, sizeof(message), err,
    fp, data);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

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👑 SEE ALSO 👑

the friends of this page, go say hi:

• setbuf(3) — set stream buffer
• explain_setbuf_or_die(3) — set stream buffer and report errors

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💜 COPYRIGHT 💜

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

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and that's the whole page, bestie — this was explain_setbuf(3) from the libexplain library's Library Functions Manual, version 1.4, dated 2010 (Peter Miller's the author, show some respect 💖). now go forth and explain your errors, you absolute main character. 🎀✨🦋