explain_feof(3)

💖 NAME 💖

okay so bestie, listen — explain_feof is literally here to explain feof(3) errors for you. that's the whole job. 🎀

(also hi, this page lives in the Library Functions Manual, and the man page name is explain_feof(3), so now you know 🫶)

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✨ SYNOPSIS ✨

#include <libexplain/feof.h>
const char *explain_feof(FILE *fp);
const char *explain_errno_feof(int errnum, FILE *fp);
void explain_message_feof(char *message, int message_size, FILE *fp);
void explain_message_errno_feof(char *message, int message_size, int errnum, FILE *fp);

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🌸 DESCRIPTION 🌸

These functions may be used to obtain explanations for errors returned by the feof(3) system call. yes queen, four whole functions, one very specific little mission 💅

🦋 explain_feof

const char *explain_feof(FILE *fp);

The explain_feof function is used to obtain an explanation of an error returned by the feof(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. it's giving overachiever and we love that for it ✨

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

• fp — The original fp, exactly as passed to the feof(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. 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. no cap, it's a shared-buffer situation.

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

if (feof(fp) < 0)
{
    fprintf(stderr, "%s\n", explain_feof(fp));
    exit(EXIT_FAILURE);
}

The above code example is available pre‐packaged as the explain_feof_or_die(3) function. pre-packaged?? iconic. convenience queen 👑

🌈 explain_errno_feof

const char *explain_errno_feof(int errnum, FILE *fp);

The explain_errno_feof function is used to obtain an explanation of an error returned by the feof(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. yes bestie, 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 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. like… errno is feral, it changes the second you look away 🙈
• fp — The original fp, exactly as passed to the feof(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 (feof(fp) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_feof(err, fp));
    exit(EXIT_FAILURE);
}

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

🎀 explain_message_feof

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

The explain_message_feof function is used to obtain an explanation of an error returned by the feof(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, she's SAFE 💅
• 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 feof(3) system call.

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

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

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

🧚 explain_message_errno_feof

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

The explain_message_errno_feof function is used to obtain an explanation of an error returned by the feof(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 boss form, fr fr 👑

• 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 feof(3) system call.

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

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

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

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👀 SEE ALSO 👀

• feof(3) — check and reset stream status
• explain_feof_or_die(3) — check and reset stream status and report errors

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📜 COPYRIGHT 📜

libexplain version 1.4 Copyright (C) 2010 Peter Miller

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okay so that's the whole thing bestie, you ate that 💖✨ the version is libexplain 1.4, it's Copyright (C) 2010 Peter Miller, and it's all filed under explain_feof(3) in the Library Functions Manual. mwah, go forth and read your error messages 🌸🦋🎀