explain_setvbuf(3)

💖 explain_setvbuf — bestie, let me explain ur setvbuf(3) errors 💖

okay so this is explain_setvbuf(3) from the Library Functions Manual and it's literally the glow-up ur error messages have been begging for ✨

🌸 NAME 🌸

explain_setvbuf — explain setvbuf(3) errors, no cap 🫶

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🎀 SYNOPSIS 🎀

#include <libexplain/setvbuf.h>
const char *explain_setvbuf(FILE *fp, char *data, int mode, size_t
size);
const char *explain_errno_setvbuf(int errnum, FILE *fp, char *data, int
mode, size_t size);
void explain_message_setvbuf(char *message, int message_size, FILE *fp,
char *data, int mode, size_t size);
void explain_message_errno_setvbuf(char *message, int message_size, int
errnum, FILE *fp, char *data, int mode, size_t size);

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🦋 DESCRIPTION 🦋

So these functions are ur lil besties when u need to get the tea on errors that came back from the setvbuf(3) system call 💅

✨ explain_setvbuf ✨

const char *explain_setvbuf(FILE *fp, char *data, int mode, size_t
size);

The explain_setvbuf function is how u get an explanation of an error that the setvbuf(3) system call returned. The bare minimum the message will contain is the value of strerror(errno), but usually it does so much better and tells u the underlying cause in more detail. it's giving detective energy 🔍

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

• fp — the original fp, exactly as passed to the setvbuf(3) system call. like, verbatim, don't touch it bestie 🙈
• data — the original data, exactly as passed to the setvbuf(3) system call.
• mode — the original mode, exactly as passed to the setvbuf(3) system call.
• size — the original size, exactly as passed to the setvbuf(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. It will be overwritten by the next call to any libexplain function which shares this buffer, including other threads. so like, don't get attached 💀

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 (setvbuf(fp, data, mode, size) < 0)
{
    fprintf(stderr, "%s\n", explain_setvbuf(fp, data, mode,
    size));
    exit(EXIT_FAILURE);
}

The above code example is available pre‐packaged as the explain_setvbuf_or_die(3) function. iconic, honestly 👑

✨ explain_errno_setvbuf ✨

const char *explain_errno_setvbuf(int errnum, FILE *fp, char *data, int
mode, size_t size);

The explain_errno_setvbuf function is used to obtain an explanation of an error returned by the setvbuf(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, different signature 💖

• errnum — the error value to be decoded, usually obtained from the errno global variable just before this function is called. This is necessary if u 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 grab it early, bestie, fr fr
• fp — the original fp, exactly as passed to the setvbuf(3) system call.
• data — the original data, exactly as passed to the setvbuf(3) system call.
• mode — the original mode, exactly as passed to the setvbuf(3) system call.
• size — the original size, exactly as passed to the setvbuf(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 (setvbuf(fp, data, mode, size) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_setvbuf(err, fp, data,
    mode, size));
    exit(EXIT_FAILURE);
}

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

✨ explain_message_setvbuf ✨

void explain_message_setvbuf(char *message, int message_size, FILE *fp,
char *data, int mode, size_t size);

The explain_message_setvbuf function is used to obtain an explanation of an error returned by the setvbuf(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. ur bringing ur own buffer to the party this time 🎀

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.
• fp — the original fp, exactly as passed to the setvbuf(3) system call.
• data — the original data, exactly as passed to the setvbuf(3) system call.
• mode — the original mode, exactly as passed to the setvbuf(3) system call.
• size — the original size, exactly as passed to the setvbuf(3) system call.

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

if (setvbuf(fp, data, mode, size) < 0)
{
    char message[3000];
    explain_message_setvbuf(message, sizeof(message), fp, data,
    mode, size);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

✨ explain_message_errno_setvbuf ✨

void explain_message_errno_setvbuf(char *message, int message_size, int
errnum, FILE *fp, char *data, int mode, size_t size);

The explain_message_errno_setvbuf function is used to obtain an explanation of an error returned by the setvbuf(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 deluxe combo — ur own buffer and ur own errno 🌈

• 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 setvbuf(3) system call.
• data — the original data, exactly as passed to the setvbuf(3) system call.
• mode — the original mode, exactly as passed to the setvbuf(3) system call.
• size — the original size, exactly as passed to the setvbuf(3) system call.

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

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

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

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🫶 SEE ALSO 🫶

• setvbuf(3) — stream buffering operations
• explain_setvbuf_or_die(3) — stream buffering operations 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, u ate that 💅✨

okay so this lil legend lives in the Library Functions Manual, it's libexplain version 1.4, and the copyright belongs to Peter Miller, (C) 2010. mwah, bye, go fix ur buffering 🦋🎀💖