получить квалификатор из записи ACL (retrieve the qualifier from an ACL entry)
Имя (Name)
acl_get_qualifier — retrieve the qualifier from an ACL entry
Библиотека (Library)
Linux Access Control Lists library (libacl, -lacl).
Синопсис (Synopsis)
#include <sys/types.h>
#include <sys/acl.h>
void *
acl_get_qualifier(acl_entry_t entry_d);
Описание (Description)
The acl_get_qualifier() function retrieves the qualifier from 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()
is 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() is a pointer to type gid_t. If the
tag type in the ACL entry referred to by entry_d is a tag type for
which a qualifier is not supported, acl_get_qualifier() returns a
value of (void *)NULL and the function fails. Subsequent operations
using the returned pointer operate on an independent copy of the
qualifier in working storage, and will not change the qualifier of
the ACL entry.
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 the void * value returned by
acl_get_qualifier() as an argument.
The argument entry_d and any other ACL entry descriptors that refer
to entries within the ACL containing the entry referred to by
entry_d continue to refer to those entries. The order of all
existing entries in the ACL containing the entry referred to by
entry_d remains unchanged.
Возвращаемое значение (Return value)
On success, the function returns a pointer to the tag qualifier
that was retrieved into ACL working storage. On error, a value of
(void *)NULL is returned and errno is set appropriately.
Ошибки (Error)
If any of the following conditions occur, the acl_get_qualifier()
function returns (void *)NULL and sets errno to the corresponding
value:
[EINVAL] 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.
[ENOMEM] The value to be returned requires more memory
than is allowed by the hardware or system-
imposed memory management constraints.
Стандарты (Conforming to)
IEEE Std 1003.1e draft 17 ('POSIX.1e', abandoned)
Смотри также (See also)
acl_create_entry(3), acl_free(3), acl_get_entry(3),
acl_get_permset(3), acl_get_tag_type(3), acl_set_permset(3),
acl_set_qualifier(3), acl_set_tag_type(3), acl(5)
