acl_set_qualifier — set the qualifier of an ACL entry


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


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


acl_set_qualifier(acl_entry_t entry_d, const void *qualifier_p);


The acl_set_qualifier() function sets the qualifier of the ACL entry indicated by the argument entry_d to the value referred to by the argument qualifier_p. 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.

Any ACL entry descriptors that refer to the entry referred to by entry_d continue to refer to that entry. This function may cause memory to be allocated. 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.


The acl_set_qualifier() function returns the value 0 if successful; otherwise the value −1 is returned and the global variable errno is set to indicate the error.


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


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.


The acl_set_qualifier() function is unable to allocate the memory required for the ACL qualifier.


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


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)


Derived from the FreeBSD manual pages written by Robert N M Watson ⟨⟩ , and adapted for Linux by Andreas Gruenbacher ⟨⟩ .

Linux ACL March 23, 2002 Linux ACL


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