Linux Access Control Lists library (libacl, -lacl).  The function
retrieves  the access ACL associated with a file or directory, or
the default ACL associated with a directory. The pathname for the
file or directory is pointed to by the argument The ACL is placed
into working storage and returns a pointer to that  storage.   In
order to read an ACL from an object, a process must have read ac‐
cess  to  the  object’s attributes.  The value of the argument is
used to indicate whether the access ACL or the default ACL  asso‐
ciated with is returned. If is ACL_TYPE_ACCESS, the access ACL of
is  returned.  If  is ACL_TYPE_DEFAULT, the default ACL of is re‐
turned. If is ACL_TYPE_DEFAULT and no default ACL  is  associated
with the directory then an ACL containing zero ACL entries is re‐
turned. If specifies a type of ACL that cannot be associated with
then  the  function  fails.  This function may cause memory to be
allocated.  The caller should free any  releasable  memory,  when
the  new  ACL is no longer required, by calling with the returned
by as an argument.  On success, this function returns  a  pointer
to the working storage.  On error, a value of is returned, and is
set appropriately.  If any of the following conditions occur, the
function  returns a value of and sets to the corresponding value:
Search permission is denied for a component of the path prefix or
the object exists and the process does not have  appropriate  ac‐
cess rights.  Argument specifies a type of ACL that cannot be as‐
sociated with The argument is not ACL_TYPE_ACCESS or ACL_TYPE_DE‐
FAULT.  The length of the argument is too long.  The named object
does  not  exist  or the argument points to an empty string.  The
ACL working storage requires more memory than is allowed  by  the
hardware or system‐imposed memory management constraints.  A com‐
ponent of the path prefix is not a directory.  The file system on
which the file identified by is located does not support ACLs, or
ACLs  are disabled.  IEEE Std 1003.1e draft 17 (“POSIX.1e”, aban‐
doned) Derived from the  FreeBSD  manual  pages  written  by  and
adapted for Linux by