ACL_CALC_MASK(3)        BSD Library Functions Manual        ACL_CALC_MASK(3)

NAME         top

     acl_calc_mask — calculate the file group class mask

LIBRARY         top

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

SYNOPSIS         top

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

     acl_calc_mask(acl_t *acl_p);

DESCRIPTION         top

     The acl_calc_mask() function calculates and sets the permissions asso‐
     ciated 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 func‐

     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         top

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

ERRORS         top

     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         top

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

SEE ALSO         top

     acl_check(3), acl_get_entry(3), acl_valid(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 for
     this manual page, see  This
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Linux ACL                      March 23, 2002                      Linux ACL