1ACL_GET_QUALIFIER(3)     BSD Library Functions Manual     ACL_GET_QUALIFIER(3)
2

NAME

4     acl_get_qualifier — retrieve the qualifier from an ACL entry
5

LIBRARY

7     Linux Access Control Lists library (libacl, -lacl).
8

SYNOPSIS

10     #include <sys/types.h>
11     #include <sys/acl.h>
12
13     void *
14     acl_get_qualifier(acl_entry_t entry_d);
15

DESCRIPTION

17     The acl_get_qualifier() function retrieves the qualifier from the ACL en‐
18     try indicated by the argument entry_d into working storage and returns a
19     pointer to that storage.
20
21     If the value of the tag type in the ACL entry referred to by entry_d is
22     ACL_USER, then the value returned by acl_get_qualifier() is a pointer to
23     type uid_t.  If the value of the tag type in the ACL entry referred to by
24     entry_d is ACL_GROUP, then the value returned by acl_get_qualifier() is a
25     pointer to type gid_t.  If the tag type in the ACL entry referred to by
26     entry_d is a tag type for which a qualifier is not supported,
27     acl_get_qualifier() returns a value of (void *)NULL and the function
28     fails. Subsequent operations using the returned pointer operate on an in‐
29     dependent copy of the qualifier in working storage, and will not change
30     the qualifier of the ACL entry.
31
32     This function may cause memory to be allocated. The caller should free
33     any releasable memory, when the new qualifier is no longer required, by
34     calling acl_free() with the void * value returned by acl_get_qualifier()
35     as an argument.
36
37     The argument entry_d and any other ACL entry descriptors that refer to
38     entries within the ACL containing the entry referred to by entry_d con‐
39     tinue to refer to those entries. The order of all existing entries in the
40     ACL containing the entry referred to by entry_d remains unchanged.
41

RETURN VALUE

43     On success, the function returns a pointer to the tag qualifier that was
44     retrieved into ACL working storage. On error, a value of (void *)NULL is
45     returned and errno is set appropriately.
46

ERRORS

48     If any of the following conditions occur, the acl_get_qualifier() func‐
49     tion returns (void *)NULL and sets errno to the corresponding value:
50
51     [EINVAL]           The argument entry_d is not a valid descriptor for an
52                        ACL entry.
53
54                        The value of the tag type in the ACL entry referenced
55                        by the argument entry_d is neither ACL_USER nor
56                        ACL_GROUP.
57
58     [ENOMEM]           The value to be returned requires more memory than is
59                        allowed by the hardware or system-imposed memory man‐
60                        agement constraints.
61

STANDARDS

63     IEEE Std 1003.1e draft 17 (“POSIX.1e”, abandoned)
64

SEE ALSO

66     acl_create_entry(3), acl_free(3), acl_get_entry(3), acl_get_permset(3),
67     acl_get_tag_type(3), acl_set_permset(3), acl_set_qualifier(3),
68     acl_set_tag_type(3), acl(5)
69

AUTHOR

71     Derived from the FreeBSD manual pages written by Robert N M Watson
72     <rwatson@FreeBSD.org>, and adapted for Linux by Andreas Gruenbacher
73     <andreas.gruenbacher@gmail.com>.
74
75Linux ACL                       March 23, 2002                       Linux ACL
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