NAME

       acl_calc_mask — calculate the file group class mask

LIBRARY

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

SYNOPSIS

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

       int
       acl_calc_mask(acl_t *acl_p);

DESCRIPTION

       The  acl_calc_mask()  function calculates and sets the permissions associated with the ACL_MASK ACL entry
       of the ACL referred to by acl_p.  The value of the new  permissions  is  the  union  of  the  permissions
       granted  by  all  entries  of  tag type ACL_GROUP, ACL_GROUP_OBJ, or ACL_USER.  If the ACL referred to by
       acl_p already contains an ACL_MASK entry, its permissions are overwritten; if  it  does  not  contain  an
       ACL_MASK entry, one is added.

       If  the  ACL  referred  to  by acl_p does not contain enough space for the new ACL entry, then additional
       working storage may be allocated. If the working storage cannot be increased  in  the  current  location,
       then  it  may  be relocated and the previous working storage is released and a pointer to the new working
       storage is returned via acl_p.

       The order of existing entries in the ACL is undefined after this function.

       Any existing ACL entry descriptors that refer to entries in the ACL continue to refer to  those  entries.
       Any existing ACL pointers that refer to the ACL referred to by acl_p continue to refer to the ACL.

RETURN VALUE

       The  acl_calc_mask()  function  returns the value 0 if successful; otherwise the value -1 is returned and
       the global variable errno is set to indicate the error.

ERRORS

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

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

       [ENOMEM]           The acl_calc_mask() function is unable to allocate the memory required for an ACL_MASK
                          ACL entry.

STANDARDS

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

SEE ALSO

       acl_check(3), acl_get_entry(3), acl_valid(3), acl(5)

AUTHOR

       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>.

Linux ACL                                        March 23, 2002                                 ACL_CALC_MASK(3)