xenial (3) acl_check.3.gz

NAME

     acl_check — check an ACL for validity

LIBRARY

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

SYNOPSIS

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

     int
     acl_check(acl_t acl, int *last);

DESCRIPTION

     The acl_check() function checks the ACL referred to by the argument acl for validity.

     The three required entries ACL_USER_OBJ, ACL_GROUP_OBJ, and ACL_OTHER must exist exactly once in the ACL.
     If the ACL contains any ACL_USER or ACL_GROUP entries, then an ACL_MASK entry is also required. The ACL may
     contain at most one ACL_MASK entry.

     The user identifiers must be unique among all entries of type ACL_USER.  The group identifiers must be
     unique among all entries of type ACL_GROUP.

     If the ACL referred to by acl is invalid, acl_check() returns a positive error code that indicates which
     type of error was detected.  The following symbolic error codes are defined:

     ACL_MULTI_ERROR       The ACL contains multiple entries that have a tag type that may occur at most once.

     ACL_DUPLICATE_ERROR   The ACL contains multiple ACL_USER entries with the same user ID, or multiple
                           ACL_GROUP entries with the same group ID.

     ACL_MISS_ERROR        A required entry is missing.

     ACL_ENTRY_ERROR       The ACL contains an invalid entry tag type.

     The acl_error() function can be used to translate error codes to text messages.

     In addition, if the pointer last is not NULL, acl_check() assigns the number of the ACL entry at which the
     error was detected to the value pointed to by last.  Entries are numbered starting with zero, in the order
     in which they would be returned by the acl_get_entry() function.

RETURN VALUE

     If successful, the acl_check() function returns 0 if the ACL referred to by acl is valid, and a positive
     error code if the ACL is invalid. Otherwise, a value of -1 is returned and the global variable errno is set
     to indicate the error.

ERRORS

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

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

STANDARDS

     This is a non-portable, Linux specific extension to the ACL manipulation functions defined in IEEE Std
     1003.1e draft 17 (“POSIX.1e”, abandoned).

SEE ALSO

     acl_valid(3), acl(5)

AUTHOR

     Written by Andreas Gruenbacher <a.gruenbacher@bestbits.at>.