.\"-
.\" Copyright (c) 2000 Robert N. M. Watson
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.Dd September 18, 2000
.Dt CAP_TO_TEXT 3
.Os
.Sh NAME
.Nm cap_to_text
.Nd convert a capability state in working storage to text
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/capability.h>
.Ft char *
.Fn cap_to_text "cap_t cap_p" "ssize_t *len_p"
.Sh DESCRIPTION
The
.Fn cap_to_text
function converts the capability state in working storage identified by
.Va cap_p
into a null terminated human-readable string.
This function allocates any memory necessary to contain the string, and
returns a pointer to the string.
If the pointer
.Va len_p
if not
.Va (size_t)NULL ,
the function shall also return the full length of the string (not including
null terminator) in the location pointed to by
.Va len_p .
The capability state in working storage idenfied by
.Va cap_p
shall be completely represented in the returned string.
.Pp
This function may cause memory to be allocated.
The caller should free any releasable memory, when the capability state
in working memory is no longer required, by calling
.Xr cap_free 3
with the
.Va cap_t
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
text form of the capability state.
Otherwise, a value of
.Va (char *)NULL
shall be returned, and
.Va errno
set to indicate the error.
.Sh ERRORS
If any of the following conditions occur, the
.Fn cap_to_text
function shall return a value of
.Va (cap_t)NULL
and set
.Va errno
to the corresponding value:
.Bl -tag -width Er
.It Bq Er EINVAL
Either the
.Va cap_p
argument does not refer to a capability state in working storage
or the
.Va len_p
argument is invalid, or both.
.It Bq Er ENOMEM
The string to be returned requires more memory than is allowed by the
hardware or system-imposed memory management constraints.
.El
.Sh SEE ALSO
.Xr cap 3 ,
.Xr cap_free 3 ,
.Xr cap_from_text 3 ,
.Xr cap_get_flag 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
.Fn cap_to_text
uses a bounded size (1024 byte) buffer in which to assemble the resulting
text string.
If the string requires more space than that buffer provides,
.Er ENOMEM
will be returned.