acl_get_qualifier(3) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | STANDARDS | SEE ALSO | AUTHOR | COLOPHON

ACL_GET_QUALIFIER(3)     Library Functions Manual   ACL_GET_QUALIFIER(3)

NAME         top

       acl_get_qualifier — retrieve the qualifier from an ACL entry

LIBRARY         top

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

SYNOPSIS         top

       <sys/types.h> <sys/acl.h> void * acl_get_qualifier(acl_entry_t
       entry_d)

DESCRIPTION         top

       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         top

       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         top

       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         top

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

SEE ALSO         top

       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         top

       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         top

       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 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-01.)  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
       man-pages@man7.org

Linux ACL                    March 23, 2002         ACL_GET_QUALIFIER(3)