Linux Access Control Lists library (libacl, -lacl).  The function
copies  the  ACL  pointed  to by from system‐managed space to the
user managed space pointed to by  The  parameter  represents  the
size  in  bytes of the buffer pointed to by The format of the ACL
placed in the buffer pointed to by is  a  contiguous,  persistent
data item, the format of which is unspecified.  It is the respon‐
sibility  of the invoker to allocate an area large enough to hold
the copied ACL. The size of the exportable,  contiguous,  persis‐
tent  form  of  the ACL may be obtained by invoking the function.
Any ACL entry descriptors that refer to an entry in the ACL  ref‐
erenced  by  continue to refer to those entries. Any existing ACL
pointers that refer to the ACL referenced by continue to refer to
the ACL.  Upon success, this function returns the number of bytes
placed in the buffer pointed to by On error, a value  of  is  re‐
turned  and is set appropriately.  If any of the following condi‐
tions occur, the function returns a value of and sets to the cor‐
responding value: The parameter is zero or negative.   The  argu‐
ment  is  not  a  valid pointer to an ACL.  The ACL referenced by
contains one or more improperly formed ACL entries, or  for  some
other  reason  cannot  be translated into the external form of an
ACL.  The 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) Derived from the FreeBSD
manual pages written by and adapted for Linux by