explain_strdup(3)

💖 explain_strdup(3) 💖

okay bestie, sit down, hydrate, because we're about to talk about explain_strdup(3) — that's the libexplain page that teaches you how to get actual explanations for your strdup(3) errors. it lives in the Library Functions Manual and it's lowkey a lifesaver. ✨

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🌸 NAME 🌸

explain_strdup — explain strdup(3) errors. that's it. that's the whole vibe. 💅

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🎀 SYNOPSIS 🎀

#include <libexplain/strdup.h>
const char *explain_strdup(const char *data);
const char *explain_errno_strdup(int errnum, const char *data);
void explain_message_strdup(char *message, int message_size, const char
*data);
void explain_message_errno_strdup(char *message, int message_size, int
errnum, const char *data);

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🦋 DESCRIPTION 🦋

so these functions? they're your little helpers for getting explanations of errors returned by the strdup(3) system call. no cap. 🫶

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✨ explain_strdup ✨

const char *explain_strdup(const char *data);

the explain_strdup function is how you obtain an explanation of an error returned by the strdup(3) system call. the least the message will contain is the value of strerror(errno), but usually it does so much better and points at the underlying cause in way more detail. it's giving overachiever, and we love that. 💖

the errno global variable is what gets used to obtain the error value to be decoded.

• data — the original data, exactly as passed to the strdup(3) system call. don't get creative with it, bestie, pass it as-is.

Returns:

the message explaining the error. this message buffer is shared by all libexplain functions which don't 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 yeah, it's giving borrowed-lipgloss energy — use it before someone else does. 😭

Note: this function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library. periodt.

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

char *result = strdup(data);
if (!result)
{
    fprintf(stderr, "%s\n", explain_strdup(data));
    exit(EXIT_FAILURE);
}

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

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💜 explain_errno_strdup 💜

const char *explain_errno_strdup(int errnum, const char *data);

the explain_errno_strdup function is used to obtain an explanation of an error returned by the strdup(3) system call. the least the message will contain is the value of strerror(errno), but usually it does much better and indicates the underlying cause in more detail. slay. ✨

• 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 grab it early, bestie, before someone stomps on it. 🙈
• data — the original data, exactly as passed to the strdup(3) system call.

Returns:

the message explaining the error. this message buffer is shared by all libexplain functions which don't 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.

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:

char *result = strdup(data);
if (!result)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_strdup(err, data));
    exit(EXIT_FAILURE);
}

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

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🌈 explain_message_strdup 🌈

void explain_message_strdup(char *message, int message_size, const char
*data);

the explain_message_strdup function is used to obtain an explanation of an error returned by the strdup(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. she understood the assignment. 💅

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. ooh, growth. 🌱
• message_size — the size in bytes of the location in which to store the returned message.
• data — the original data, exactly as passed to the strdup(3) system call.

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

char *result = strdup(data);
if (!result)
{
    char message[3000];
    explain_message_strdup(message, sizeof(message), data);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

the above code example is available pre‐packaged as the explain_strdup_or_die(3) function. 🎀

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⭐ explain_message_errno_strdup ⭐

void explain_message_errno_strdup(char *message, int message_size, int
errnum, const char *data);

the explain_message_errno_strdup function is used to obtain an explanation of an error returned by the strdup(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. main character behavior 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. we stan a safe queen. ✨
• 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. save it before it gets snatched, iykyk. 😭
• data — the original data, exactly as passed to the strdup(3) system call.

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

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

the above code example is available pre‐packaged as the explain_strdup_or_die(3) function. 💜

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🫶 SEE ALSO 🫶

• strdup(3) — duplicate a string
• explain_strdup_or_die(3) — duplicate a string and report errors

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👑 COPYRIGHT 👑

libexplain version 1.4 Copyright (C) 2009 Peter Miller

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and that's the whole page, bestie!! 🦋✨ if you ever get a cursed strdup(3) error and you're just staring at errno like 👁️👄👁️, now you know exactly which explain function to call. go forth, decode your errors, be the main character of your own strace. mwah. 💖💅🌸

— sign-off brought to you by libexplain version 1.4, Copyright (C) 2009 Peter Miller, and the fact that this is the explain_strdup(3) page. 🎀