acl_copy_ext(3) — Linux manual page


ACL_COPY_EXT(3)       BSD Library Functions Manual       ACL_COPY_EXT(3)

NAME         top

     acl_copy_ext — copy an ACL from internal to external representation

LIBRARY         top

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

SYNOPSIS         top

     #include <sys/types.h>
     #include <sys/acl.h>

     acl_copy_ext(void *buf_p, acl_t acl, ssize_t size);

DESCRIPTION         top

     The acl_copy_ext() function copies the ACL pointed to by acl from
     system-managed space to the user managed space pointed to by buf_p.
     The size parameter represents the size in bytes of the buffer
     pointed to by buf_p.  The format of the ACL placed in the buffer
     pointed to by buf_p is a contiguous, persistent data item, the
     format of which is unspecified.  It is the responsibility of the
     invoker to allocate an area large enough to hold the copied ACL.
     The size of the exportable, contiguous, persistent form of the ACL
     may be obtained by invoking the acl_size() function.

     Any ACL entry descriptors that refer to an entry in the ACL
     referenced by acl continue to refer to those entries. Any existing
     ACL pointers that refer to the ACL referenced by acl continue to
     refer to the ACL.

RETURN VALUE         top

     Upon success, this function returns the number of bytes placed in
     the buffer pointed to by buf_p.  On error, a value of (ssize_t)-1
     is returned and errno is set appropriately.

ERRORS         top

     If any of the following conditions occur, the acl_copy_ext()
     function returns a value of (ssize_t)-1 and sets errno to the
     corresponding value:

     [EINVAL]           The size parameter is zero or negative.

                        The argument acl is not a valid pointer to an

                        The ACL referenced by acl contains one or more
                        improperly formed ACL entries, or for some other
                        reason cannot be translated into the external
                        form of an ACL.

     [ERANGE]           The size parameter is greater than zero but
                        smaller than the length of the contiguous,
                        persistent form of the ACL.

STANDARDS         top

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

SEE ALSO         top

     acl_copy_int(3), acl_size(3), acl(5)

AUTHOR         top

     Derived from the FreeBSD manual pages written by Robert N M Watson
     <>, and adapted for Linux by Andreas Gruenbacher

COLOPHON         top

     This page is part of the acl (manipulating access control lists)
     project.  Information about the project can be found at  If you have a bug report
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Linux ACL                    March 23, 2002                    Linux ACL