ACL_SET_QUALIFIER(3)

💅 ACL_SET_QUALIFIER(3) — Library Functions Manual

okay bestie, pull up a chair, we're doing a manual page from the Linux Access Control Lists library (that's libacl, link it with -lacl) 🎀 and honestly? it's a good one. the function is acl_set_qualifier, and the whole vibe is: you have an ACL entry, and you want to change who or what it's about. iconic behavior. let's go ✨

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🌸 NAME 🌸

acl_set_qualifier — set the qualifier of an ACL entry

like, the qualifier. the little "which user" / "which group" part. the who in the who gets what. 🫶

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📚 LIBRARY 📚

Linux Access Control Lists library (libacl, -lacl).

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🦋 SYNOPSIS 🦋

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

int
acl_set_qualifier(acl_entry_t entry_d, const void *qualifier_p);

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✨ DESCRIPTION ✨

so. acl_set_qualifier() sets the qualifier of the ACL entry pointed at by the argument entry_d to the value referred to by the argument qualifier_p. simple as that. 💖

here's the part you cannot fumble, and i say this with love:

• if the value of the tag type in the ACL entry referred to by entry_d is ACL_USER, then the value referred to by qualifier_p shall be of type uid_t 👑
• if the value of the tag type in the ACL entry referred to by entry_d is ACL_GROUP, then the value referred to by qualifier_p shall be of type gid_t 🌈
• if the value of the tag type in the ACL entry referred to by entry_d is a tag type for which a qualifier is not supported, acl_set_qualifier() returns an error. no qualifier for you, babe. 💀

also important, and it's giving "your pointers still work":

Any ACL entry descriptors that refer to the entry referred to by entry_d continue to refer to that entry. no dangling, no ghosting, we love that for them 🫶

and the memory tea 🍓: this function may cause memory to be allocated. so the caller should free any releasable memory, when the ACL is no longer required, by calling acl_free() with a pointer to the ACL as argument. clean up after yourself, bestie, it's self care. ✨

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💜 RETURN VALUE 💜

acl_set_qualifier() returns the value 0 if successful 🎉 otherwise the value -1 is returned and the global variable errno is set to indicate the error 😭

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💀 ERRORS 💀

if any of the following conditions occur, the acl_set_qualifier() function returns -1 and sets errno to the corresponding value:

• [EINVAL] — any of these, and they're all "girl what":
  • The argument entry_d is not a valid descriptor for an ACL entry.
  • The value of the tag type in the ACL entry referenced by the argument entry_d is neither ACL_USER nor ACL_GROUP.
  • The value pointed to by the argument qualifier_p is not valid.
• [ENOMEM] — The acl_set_qualifier() function is unable to allocate the memory required for the ACL qualifier. (the machine said "no 💀")

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👑 STANDARDS 👑

IEEE Std 1003.1e draft 17 (“POSIX.1e”, abandoned)

abandoned. the standard got ghosted. we still use it anyway. main character energy 🧚

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🔥 SEE ALSO 🔥

• acl_create_entry(3)
• acl_free(3)
• acl_get_permset(3)
• acl_get_qualifier(3)
• acl_get_tag_type(3)
• acl_set_entry(3)
• acl_set_permset(3)
• acl_set_tag_type(3)
• acl(5)

iykyk, go read the whole squad 📖

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🎀 AUTHOR 🎀

Derived from the FreeBSD manual pages written by Robert N M Watson <rwatson@FreeBSD.org>, and adapted for Linux by Andreas Gruenbacher <andreas.gruenbacher@gmail.com>. legends, honestly. thank you for your service 🫡💖

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and that's the page!! this one's from Linux ACL, dated March 23, 2002 — vintage, but still slaying. go set some qualifiers, bestie, you got this 🌟💅