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


acl_copy_ext — copy an ACL from internal to external representation


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


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


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


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.


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.


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:


The size parameter is zero or negative.

The argument acl is not a valid pointer to an ACL.

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.


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


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


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


Derived from the FreeBSD manual pages written by Robert N M Watson <rwatson [AT]>, and adapted for Linux by Andreas Gruenbacher <andreas.gruenbacher [AT]>.

Linux ACL March 23, 2002 Linux ACL