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.
If any of the following conditions occur, the acl_get_qualifier()
function returns (void *)NULL and sets errno to the corresponding
[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.
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 2021-04-01. (At that
time, the date of the most recent commit that was found in the
repository was 2021-03-16.) 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 email@example.com
Linux ACL March 23, 2002 Linux ACL