acl_copy_ext(3) BSD Library Functions Manual acl_copy_ext(3)
NAME
acl_copy_ext, acl_copy_ext_native, acl_copy_int, acl_copy_int_native,
acl_size -- convert an ACL to and from an external representation
SYNOPSIS
#include <sys/types.h>
#include <sys/acl.h>
ssize_t
acl_copy_ext(void *buf, acl_t acl, ssize_t size);
ssize_t
acl_copy_ext_native(void *buf, acl_t acl, ssize_t size);
acl_t
acl_copy_int(const void *buf);
acl_t
acl_copy_int_native(const void *buf);
ssize_t
acl_size(acl_t acl);
DESCRIPTION
The acl_copy_ext() and acl_copy_ext_native() functions convert the ACL
given by the argument acl into a binary external representation that can
be saved to a file, passed to another program, etc. This external repre-
sentation is written to the buffer pointed to by the argument buf, which
is assumed to have at least the number of contiguous bytes passed in the
size argument. The number of bytes actually written is returned.
The acl_copy_ext() function writes data in big-endian byte-order, and so
is portable across machines with different byte-order. To the contrary,
the acl_copy_ext_native() function uses the machine's native byte-order,
and so is only portable to machines of like byte-order.
The acl_copy_int() and acl_copy_int_native() functions do the reverse
conversion; the ACL represented by the external representation passed in
the argument buf, is returned. The acl_copy_int() function expects an
external representation in big-endian byte-order (as returned by
acl_copy_ext()), while acl_copy_int_native() expects an external repre-
sentation in native byte-order (as returned by acl_copy_ext_native()).
The acl_size() function returns the corresponding external representation
size, in bytes, for the given ACL passed in the argument acl. This size
can be used to allocate sufficient memory for the buffer in subsequent
calls to acl_copy_ext() and acl_copy_ext_native().
RETURN VALUES
Upon successful completion, the acl_copy_ext() and acl_copy_ext_native()
functions shall return the number of bytes actually written to the
buffer. Otherwise, a value of -1 shall be returned and errno shall be
set to indicate the error.
Upon successful completion, the acl_copy_int() and acl_copy_int_native()
functions shall return the ACL represented by the external representation
passed in the buffer. Otherwise, a value of (acl_t)NULL shall be
returned and errno shall be set to indicate the error.
Upon successful completion, the acl_size() function shall return the size
of the external representation. Otherwise, a value of -1 shall be
returned and errno shall be set to indicate the error.
ERRORS
The acl_copy_ext() and acl_copy_ext_native() functions fail if:
[EINVAL] Argument acl does not point to a valid ACL.
[ERANGE] The given buffer is too small to contain the converted
external representation.
The acl_copy_int() and acl_copy_int_native() functions fail if:
[EINVAL] The buffer does not contain a valid external represen-
tation.
The acl_size() function fails if:
[EINVAL] Argument acl does not point to a valid ACL.
NOTE
While the external representation may use pre-existing data structures,
no assumptions on the internal structure should be made.
The acl_to_text(3) and acl_from_text(3) functions also convert to and
from a different external representation, a human-readable string. Nei-
ther of these representations are cross-platform, lacking a cross-plat-
form standard.
SEE ALSO
acl(3), acl_from_text(3), acl_to_text(3)
AUTHORS
Michael Smith
Robert N M Watson
February 3, 2011
Mac OS X 10.8 - Generated Sun Aug 26 09:19:22 CDT 2012