ACL_GET_QUALIFIER(3)

NAME
acl_get_qualifier - retrieve the qualifier from an ACL entry

LIBRARY
libc

SYNOPSIS
#include <sys/types.h>
#include <sys/acl.h>
void *
acl_get_qualifier(acl_entry_t entry_d);

DESCRIPTION
The acl_get_qualifier() function is a POSIX.1e call that retrieves the qualifier of the tag for the ACL entry indicated by the argument entry_d into working storage and returns a pointer to that storage.

If the value of the tag type in the ACL entry referred to by entry_d is ACL_USER, then the value returned by acl_get_qualifier() will be a pointer to 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 returned by acl_get_qualifier() will be a pointer to type gid_t.

If the value of the tag type in the ACL entry referred to by entry_d is ACL_UNDEFINED_TAG, ACL_USER_OBJ, ACL_GROUP_OBJ, ACL_OTHER, ACL_MASK, or an implementation-defined value for which a qualifier is not supported, then acl_get_qualifier() will return a value of (void *)NULL and the function will fail.

This function may cause memory to be allocated. The caller should free any releasable memory, when the new qualifier is no longer required, by calling acl_free() with void * as the argument.

RETURN VALUES
The acl_get_qualifier() function returns a pointer to the allocated storage if successful; otherwise a NULL pointer is returned and the global variable errno is set to indicate the error.

ERRORS
The acl_get_qualifier() fails if:

[EINVAL]
    Argument entry_d does not point to a valid descriptor for an ACL entry. The value of the tag type in the ACL entry referenced by argument entry_d is not ACL_USER or ACL_GROUP.

[ENOMEM]
    The value to be returned requires more memory than is allowed by the hardware or system-imposed memory management constraints.

SEE ALSO
acl(3), acl_create_entry(3), acl_free(3), acl_get_entry(3), acl_get_tag_type(3), acl_set_qualifier(3), acl_set_tag_type(3), posix1e(3)

STANDARDS
POSIX.1e is described in IEEE POSIX.1e draft 17.

HISTORY
POSIX.1e support was introduced in FreeBSD 4.0. The acl_get_qualifier() function was added in FreeBSD 5.0.

AUTHORS
The acl_get_qualifier() function was written by Chris D. Faulhaber <jedgar@fxp.org>.