ACL_FROM_MODE(3)

💖 ACL_FROM_MODE(3) 💖

okay bestie, so this one is acl_from_mode from the Library Functions Manual — it lives in section 3, it's the lil glow-up function that turns boring old file permission bits into a whole entire ACL. no cap.

✨ NAME ✨

acl_from_mode — create an ACL from file permission bits 🎀

📚 LIBRARY 📚

Linux Access Control Lists library (that's libacl, and you link it with -lacl) 🦋

🌸 SYNOPSIS 🌸

#include <sys/types.h>
#include <acl/libacl.h>

acl_t
acl_from_mode(mode_t mode);

💅 DESCRIPTION 💅

So the acl_from_mode() function creates a minimal ACL, and when I say minimal I mean it is giving bare minimum, it has literally just three entries:

• one with tag type ACL_USER_OBJ
• one with tag type ACL_GROUP_OBJ
• one with tag type ACL_OTHER

and the permissions on those entries correspond to the owner, group, and other permission bits of its argument mode. that's it. that's the whole function. iconic behaviour honestly 🌈

⭐ RETURN VALUE ⭐

On success, this function returns a pointer to the working storage. 🫶

On error, a value of (acl_t)NULL is returned, and errno is set appropriately. sad girl hours 😭

💀 ERRORS 💀

If any of the following conditions occur, the acl_from_mode() function returns a value of (acl_t)NULL and sets errno to the corresponding value:

• [ENOMEM] — the ACL working storage requires more memory than is allowed by the hardware or system-imposed memory management constraints. (she's asking for too much and the system said no 🙈)

👑 STANDARDS 👑

This is a non-portable, Linux specific extension to the ACL manipulation functions defined in IEEE Std 1003.1e draft 17 (“POSIX.1e”, abandoned). yes bestie, abandoned. we don't talk about it. 💀

🔥 SEE ALSO 🔥

• acl_equiv_mode(3)
• acl_get_file(3)
• acl(5)

🎀 AUTHOR 🎀

Written by Andreas Gruenbacher <andreas.gruenbacher@gmail.com>. thank you king 👑

and that's the whole page, bestie — from Linux ACL, dated March 23, 2002, and it's the ACL_FROM_MODE(3) page. go forth and make minimal ACLs, ily, mwah 💖🧚🌸