NAME
extattr_namespace_to_string,
extattr_string_to_namespace —
convert an extended attribute namespace
identifier to a string and vice versa
LIBRARY
library “libutil”
SYNOPSIS
#include
<sys/extattr.h>
#include <libutil.h>
int
extattr_namespace_to_string(int
attrnamespace, char
**string);
int
extattr_string_to_namespace(const
char *string, int
*attrnamespace);
DESCRIPTION
Theextattr_namespace_to_string()
function converts a VFS extended attribute identifier to a human-readable
string; the
extattr_string_to_namespace()
function undoes the aforementioned operation, and converts a human-readable
string representing a namespace to a namespace identifier. Although a file
system may implement arbitrary namespaces, these functions only support the
EXTATTR_NAMESPACE_USER (“user”) and
EXTATTR_NAMESPACE_SYSTEM (“system”)
namespaces, which are defined in
extattr(9).
These functions are meant to be
used in error reporting and other interactive tasks. For example, instead of
printing the integer identifying an extended attribute in an error message,
a program might use
extattr_namespace_to_string()
to obtain a human-readable representation. Likewise, instead of requiring a
user to enter the integer representing a namespace, an interactive program
might ask for a name and use
extattr_string_to_namespace()
to get the desired identifier.
RETURN VALUES
If any of the calls are unsuccessful, the value -1 is returned and the global variable errno is set to indicate the error.
ERRORS
- [
EINVAL] - The requested namespace could not be identified.
SEE ALSO
HISTORY
Extended attribute support was developed as part of the TrustedBSD Project, and introduced in FreeBSD 5.0. It was developed to support security extensions requiring additional labels to be associated with each file or directory.