explain_rename(3)

✨ explain_rename ✨

okay bestie, sit down, hydrate, because today we're decoding rename(2) errors and honestly? it's giving main character energy 🎀 this is part of the libexplain library functions manual, and it's literally here to tell you why your rename went off the rails.

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🌸 NAME 🌸

explain_rename — explain rename(2) errors 💅

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🦋 SYNOPSIS 🦋

#include <libexplain/rename.h>
const char *explain_rename(const char *oldpath, const char *newpath);
const char *explain_errno_rename(int errnum, const char *oldpath, const
char *newpath);
void explain_message_rename(char *message, int message_size, const char
*oldpath, const char *newpath);
void explain_message_errno_rename(char *message, int message_size, int
errnum, const char *oldpath, const char *newpath);

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💖 DESCRIPTION 💖

so the functions declared in the <libexplain/rename.h> include file are here to explain errors returned by the rename(2) system call. that's it. that's the vibe. no cap.

🌟 explain_rename 🌟

const char *explain_rename(const char *oldpath, const char *newpath);

the explain_rename function is used to obtain an explanation of an error returned by the rename(2) function. 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, it actually spills the tea 🍵

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

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

if (rename(oldpath, rewpath) < 0)
{
    fprintf(stderr, "%s\n", explain_rename(oldpath, newpath));
    exit(EXIT_FAILURE);
}

• oldpath — the original oldpath, exactly as passed to the rename(2) system call.
• newpath — the original newpath, exactly as passed to the rename(2) 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 😭

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

💫 explain_errno_rename 💫

const char *explain_errno_rename(int errnum, const char *oldpath, const
char *newpath);

the explain_errno_rename function is used to obtain an explanation of an error returned by the rename(2) function. the least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail. it understood the assignment fr fr ✨

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

if (rename(oldpath, newpath) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_rename(err, oldpath,
        newpath));
    exit(EXIT_FAILURE);
}

• 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. (sneaky little guys, honestly.)
• oldpath — the original oldpath, exactly as passed to the rename(2) system call.
• newpath — the original newpath, exactly as passed to the rename(2) 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. bestie it is shared, protect your peace 🫶

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

🎀 explain_message_rename 🎀

void explain_message_rename(char *message, int message_size, const char
*oldpath, const char *newpath);

the explain_message_rename function is used to obtain an explanation of an error returned by the rename(2) function. 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. iconic behaviour.

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

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

if (rename(oldpath, newpath) < 0)
{
    char message[3000];
    explain_message_rename(message, sizeof(message), oldpath,
        newpath);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

• message — the location in which to store the returned message. because a message return buffer has been supplied, this function is thread safe, if the buffer is thread safe. look at her go, she's growing up 😭
• message_size — the size in bytes of the location in which to store the returned message.
• oldpath — the original oldpath, exactly as passed to the rename(2) system call.
• newpath — the original newpath, exactly as passed to the rename(2) system call.

🌈 explain_message_errno_rename 🌈

void explain_message_errno_rename(char *message, int message_size, int
errnum, const char *oldpath, const char *newpath);

the explain_message_errno_rename function is used to obtain an explanation of an error returned by the rename(2) function. the least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail. the way she knows things 🔥

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

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

• message — the location in which to store the returned message. because a message return buffer has been supplied, this function is thread safe, given a thread safe buffer.
• 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.
• oldpath — the original oldpath, exactly as passed to the rename(2) system call.
• newpath — the original newpath, exactly as passed to the rename(2) system call.

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👑 COPYRIGHT 👑

libexplain version 1.4 Copyright (C) 2008 Peter Miller

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💜 AUTHOR 💜

written by Peter Miller <pmiller@opensource.org.au>

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and that's the whole page, bestie 🦋 go forth and debug with confidence. this was explain_rename(3) from libexplain version 1.4, copyright (C) 2008 Peter Miller — mwah, slay, take care of your errno 💅✨