freebsd-nq/lib/libc/posix1e/acl_to_text.3

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.Dd June 25, 2009
.Dt ACL_TO_TEXT 3
.Os
.Sh NAME
.Nm acl_to_text ,
.Nm acl_to_text_np
.Nd convert an ACL to text
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/types.h
.In sys/acl.h
.Ft char *
.Fn acl_to_text "acl_t acl" "ssize_t *len_p"
.Ft char *
.Fn acl_to_text_np "acl_t acl" "ssize_t *len_p" "int flags"
.Sh DESCRIPTION
The
.Fn acl_to_text
and
.Fn acl_to_text_np
functions translate the ACL pointed to by argument
.Va acl
into a NULL terminated character string.
If the pointer
.Va len_p
is not NULL, then the function shall return the length of the string (not
including the NULL terminator) in the location pointed to by
.Va len_p .
If the ACL is POSIX.1e, the format of the text string returned by
.Fn acl_to_text
shall be the POSIX.1e long ACL form.  If the ACL is NFSv4, the format
of the text string shall be the compact form, unless the
.Va ACL_TEXT_VERBOSE
flag is given.
.Pp
The flags specified are formed by
.Em or Ns 'ing
the following values
.Bl -column -offset 3n "ACL_TEXT_NUMERIC_IDS"
.It ACL_TEXT_VERBOSE Ta "Format ACL using verbose form"
.It ACL_TEXT_NUMERIC_IDS Ta "Do not resolve IDs into user or group names"
.It ACL_TEXT_APPEND_ID Ta "In addition to user and group names, append numeric IDs"
.El
.Pp
This function allocates any memory necessary to contain the string and
returns a pointer to the string.
The caller should free any releasable
memory, when the new string is no longer required, by calling
.Xr acl_free 3
with the
.Va (void*)char
as an argument.
.Sh IMPLEMENTATION NOTES
.Fx Ns 's
support for POSIX.1e interfaces and features is still under
development at this time.
.Sh RETURN VALUES
Upon successful completion, the function shall return a pointer to the
long text form of an ACL.
Otherwise, a value of
.Va (char*)NULL
shall be returned and
.Va errno
shall be set to indicate the error.
.Sh ERRORS
If any of the following conditions occur, the
.Fn acl_to_text
function shall return a value of
.Va (acl_t)NULL
and set
.Va errno
to the corresponding value:
.Bl -tag -width Er
.It Bq Er EINVAL
Argument
.Va acl
does not point to a valid ACL.
.Pp
The ACL denoted by
.Va acl
contains one or more improperly formed ACL entries, or for some other
reason cannot be translated into a text form of an ACL.
.It Bq Er ENOMEM
The character string to be returned requires more memory than is allowed
by the hardware or software-imposed memory management constraints.
.El
.Sh SEE ALSO
.Xr acl 3 ,
.Xr acl_free 3 ,
.Xr acl_from_text 3 ,
.Xr posix1e 3
.Sh STANDARDS
POSIX.1e is described in IEEE POSIX.1e draft 17.
Discussion
of the draft continues on the cross-platform POSIX.1e implementation
mailing list.
To join this list, see the
.Fx
POSIX.1e implementation
page for more information.
.Sh HISTORY
POSIX.1e support was introduced in
.Fx 4.0 ,
and development continues.
.Sh AUTHORS
.An Robert N M Watson
.Sh BUGS
The
.Fn acl_from_text
and
.Fn acl_to_text
functions
rely on the
.Xr getpwent 3
library calls to manage username and uid mapping, as well as the
.Xr getgrent 3
library calls to manage groupname and gid mapping.
These calls are not
thread safe, and so transitively, neither are
.Fn acl_from_text
and
.Fn acl_to_text .
These functions may also interfere with stateful
calls associated with the
.Fn getpwent
and
.Fn getgrent
calls.