explain_tempnam(3)

💖 explain_tempnam — bestie, let's decode ur tempnam(3) errors 💖

okay so this is a page from the Library Functions Manual (yes, the libexplain crew, ily), and it's all about turning those cryptic tempnam(3) failures into actual human sentences. no more staring at a bare NULL like 👁️👄👁️. let's go.

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✨ NAME ✨

explain_tempnam — explain tempnam(3) errors

like, it literally explains the errors. the name ate and left no crumbs.

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🌸 SYNOPSIS 🌸

#include <libexplain/tempnam.h>
const char *explain_tempnam(const char *dir, const char *prefix);
const char *explain_errno_tempnam(int errnum, const char *dir, const char *prefix);
void explain_message_tempnam(char *message, int message_size, const char *dir, const char *prefix);
void explain_message_errno_tempnam(char *message, int message_size, int errnum, const char *dir, const char *prefix);

four functions, one mission: tell u what actually went wrong 🫶

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🦋 DESCRIPTION 🦋

These functions may be used to obtain explanations for errors returned by the tempnam(3) system call. that's the whole vibe. u call them, they hand u back words that make sense. iconic behavior honestly.

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💅 explain_tempnam

const char *explain_tempnam(const char *dir, const char *prefix);

The explain_tempnam function is used to obtain an explanation of an error returned by the tempnam(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. like, the bare minimum is the strerror(errno) text, but bestie it usually pops OFF with the real tea.

The errno global variable will be used to obtain the error value to be decoded. so it's reading errno for u, no need to pass it in.

• dir — The original dir, exactly as passed to the tempnam(3) system call.
• prefix — The original prefix, exactly as passed to the tempnam(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. 💀 so like, if u and ur thread besties are all grabbing at the same buffer… it's giving chaos. be careful.

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

char *result = tempnam(dir, prefix);
if (!result)
{
    fprintf(stderr, "%s\n", explain_tempnam(dir, prefix));
    exit(EXIT_FAILURE);
}

The above code example is available pre‐packaged as the explain_tempnam_or_die(3) function. pre-packaged!! like a lil snack u didn't have to cook urself 🍓

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✨ explain_errno_tempnam

const char *explain_errno_tempnam(int errnum, const char *dir, const char *prefix);

The explain_errno_tempnam function is used to obtain an explanation of an error returned by the tempnam(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 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. lowkey the whole point: u grabbed errno early bc something else was about to stomp all over it 🙈
• dir — The original dir, exactly as passed to the tempnam(3) system call.
• prefix — The original prefix, exactly as passed to the tempnam(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. (same shared-buffer drama, same warning, no cap.)

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

char *result = tempnam(dir, prefix);
if (!result)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_tempnam(err, dir,
    prefix));
    exit(EXIT_FAILURE);
}

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

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🎀 explain_message_tempnam

void explain_message_tempnam(char *message, int message_size, const char *dir, const char *prefix);

The explain_message_tempnam function is used to obtain an explanation of an error returned by the tempnam(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. ur own buffer = ur own peace ✨
• message_size — The size in bytes of the location in which to store the returned message.
• dir — The original dir, exactly as passed to the tempnam(3) system call.
• prefix — The original prefix, exactly as passed to the tempnam(3) system call.

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

char *result = tempnam(dir, prefix);
if (!result)
{
    char message[3000];
    explain_message_tempnam(message, sizeof(message), dir,
    prefix);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

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

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👑 explain_message_errno_tempnam

void explain_message_errno_tempnam(char *message, int message_size, int errnum, const char *dir, const char *prefix);

The explain_message_errno_tempnam function is used to obtain an explanation of an error returned by the tempnam(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.
• dir — The original dir, exactly as passed to the tempnam(3) system call.
• prefix — The original prefix, exactly as passed to the tempnam(3) system call.

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

char *result = tempnam(dir, prefix);
if (!result)
{
    int err = errno;
    char message[3000];
    explain_message_errno_tempnam(message, sizeof(message), err,
    dir, prefix);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre‐packaged as the explain_tempnam_or_die(3) function. bestie the _or_die variant does the whole song and dance for u, go check it 💜

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🌈 SEE ALSO 🌈

• tempnam(3) — create a name for a temporary file
• explain_tempnam_or_die(3) — create a name for a temporary file and report errors

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💖 COPYRIGHT 💖

okay so the legal bit, and we respect it:

• libexplain version 1.4
• Copyright (C) 2009 Peter Miller

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and that's the whole page, bestie 🧚✨ it's giving libexplain version 1.4, Copyright (C) 2009 Peter Miller, filed under the Library Functions Manual — go forth and explain ur errors, u absolute icon 👑💅