acl_get_qualifier(3) — Linux manual page
ACL_GET_QUALIFIER(3) Library Functions Manual ACL_GET_QUALIFIER(3)
NAME
acl_get_qualifier — retrieve the qualifier from an ACL entry
LIBRARY
Linux Access Control Lists library (libacl, -lacl).
SYNOPSIS
<sys/types.h> <sys/acl.h> void * acl_get_qualifier(acl_entry_t
entry_d)
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.
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.
ERRORS
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.
STANDARDS
IEEE Std 1003.1e draft 17 (“POSIX.1e”, abandoned)
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)
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>.
COLOPHON
This page is part of the acl (manipulating access control lists)
project. Information about the project can be found at
http://savannah.nongnu.org/projects/acl. If you have a bug
report for this manual page, see
⟨http://savannah.nongnu.org/bugs/?group=acl⟩. This page was
obtained from the project's upstream Git repository
⟨git://git.savannah.nongnu.org/acl.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-04-25.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
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