explain_acl_set_fd(3)

💖 explain_acl_set_fd(3) — Library Functions Manual 💖

okay bestie, welcome to the libexplain corner of the manual, where we explain why acl_set_fd(3) said no. this whole page lives in the Library Functions Manual, and it's about one very specific kind of bestie behaviour: turning a cryptic error into an actual sentence. 🎀

---

✨ NAME ✨

explain_acl_set_fd — explain acl_set_fd(3) errors

like, it literally exists to tell you why your ACL call flopped. no cap. 🦋

---

✨ SYNOPSIS ✨

#include <libexplain/acl_set_fd.h>
const char *explain_acl_set_fd(int fildes, acl_t acl);
const char *explain_errno_acl_set_fd(int errnum, int fildes, acl_t acl);
void explain_message_acl_set_fd(char *message, int message_size, int
fildes, acl_t acl);
void explain_message_errno_acl_set_fd(char *message, int message_size,
int errnum, int fildes, acl_t acl);

four little functions, four little vibes. 💅

---

✨ DESCRIPTION ✨

These functions may be used to obtain explanations for errors returned by the acl_set_fd(3) system call. that's the whole assignment and they ate. 🌈

---

🌸 explain_acl_set_fd 🌸

const char *explain_acl_set_fd(int fildes, acl_t acl);

The explain_acl_set_fd function is used to obtain an explanation of an error returned by the acl_set_fd(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. 😭💖

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

• fildes — The original fildes, exactly as passed to the acl_set_fd(3) system call.
• acl — The original acl, exactly as passed to the acl_set_fd(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, be careful out there in multithreaded land, bestie.

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

if (acl_set_fd(fildes, acl) < 0)
{
    fprintf(stderr, "%s\n", explain_acl_set_fd(fildes, acl));
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_acl_set_fd_or_die(3) function. pre-packaged?? she's convenient, she's ready to go, she's iconic. 👑

---

🌸 explain_errno_acl_set_fd 🌸

const char *explain_errno_acl_set_fd(int errnum, int fildes, acl_t acl);

The explain_errno_acl_set_fd function is used to obtain an explanation of an error returned by the acl_set_fd(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. 🫶 so grab that errno FAST, she will not wait for you.
• fildes — The original fildes, exactly as passed to the acl_set_fd(3) system call.
• acl — The original acl, exactly as passed to the acl_set_fd(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. 💀 yeah. same warning, same energy.

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

if (acl_set_fd(fildes, acl) < 0)
{
    int err = errno;
    fprintf(stderr, "%s\n", explain_errno_acl_set_fd(err, fildes,
    acl));
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_acl_set_fd_or_die(3) function.

---

🌸 explain_message_acl_set_fd 🌸

void explain_message_acl_set_fd(char *message, int message_size, int
fildes, acl_t acl);

The explain_message_acl_set_fd function is used to obtain an explanation of an error returned by the acl_set_fd(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. 🎀 bestie you bring your own buffer and suddenly we're safe!! growth!!
• message_size — The size in bytes of the location in which to store the returned message.
• fildes — The original fildes, exactly as passed to the acl_set_fd(3) system call.
• acl — The original acl, exactly as passed to the acl_set_fd(3) system call.

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

if (acl_set_fd(fildes, acl) < 0)
{
    char message[3000];
    explain_message_acl_set_fd(message, sizeof(message), fildes,
    acl);
    fprintf(stderr, "%s\n", message);
    exit(EXIT_FAILURE);
}

The above code example is available pre-packaged as the explain_acl_set_fd_or_die(3) function.

---

🌸 explain_message_errno_acl_set_fd 🌸

void explain_message_errno_acl_set_fd(char *message, int message_size,
int errnum, int fildes, acl_t acl);

The explain_message_errno_acl_set_fd function is used to obtain an explanation of an error returned by the acl_set_fd(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. 🫶
• fildes — The original fildes, exactly as passed to the acl_set_fd(3) system call.
• acl — The original acl, exactly as passed to the acl_set_fd(3) system call.

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

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

The above code example is available pre-packaged as the explain_acl_set_fd_or_die(3) function. ✨

---

✨ SEE ALSO ✨

• acl_set_fd(3) — set an ACL by file descriptor
• explain_acl_set_fd_or_die(3) — set an ACL by file descriptor and report errors

yes bestie, go read those too, they're the supporting cast and they understood the assignment. 💜

---

✨ COPYRIGHT ✨

libexplain version 1.4 Copyright (C) 2013 Peter Miller

---

and that's the whole page, bestie!! 🦋🌸 libexplain version 1.4, copyright 2013, Peter Miller — the icon, the legend, the person who wrote this so we don't have to guess why acl_set_fd(3) ghosted us. mwah. 💅🎀⭐