#include <attr/attributes.h>
int attr_get (const char *path, const char *attrname, char
*attrvalue, int *valuelength, int flags);int attr_getf (int fd, const char
*attrname, char *attrvalue, int *valuelength, int flags);
DescriptionThe
attr_get and attr_getf functions provide a way to retrieve the value of
an attribute. Path points to a path name for a filesystem object, and fd
refers to the file descriptor associated with a file. If the attribute attrname
exists, the value associated with it will be copied into the attrvalue
buffer. The valuelength argument is an input/output argument that on the
call to attr_get should contain the maximum size of attribute value the
process is willing to accept. On return, the valuelength will have been
modified to show the actual size of the attribute value returned. The flags
argument can contain the following symbols bitwise OR’ed together:
ATTR_ROOT
Look for attrname in the root address space, not in the user address space.
(limited to use by super-user only) ATTR_DONTFOLLOW Do not follow symbolic
links when resolving a path on an attr_get function call. The default is
to follow symbolic links. attr_get will fail if one or more of the following
are true:
[ENOATTR] The attribute name given is not associated with the
indicated filesystem object. [E2BIG] The value of the given attribute is
too large to fit into the buffer. The integer that the valuelength argument
points to has been modified to show the actual number of bytes that would
be required to store the value of that attribute. [ENOENT] The named file
does not exist. [EPERM] The effective user ID does not match the owner
of the file and the effective user ID is not super-user. [ENOTDIR] A component
of the path prefix is not a directory. [EACCES] Search permission is denied
on a component of the path prefix. [EINVAL] A bit was set in the flag argument
that is not defined for this system call. [EFAULT] Path, attrname, attrvalue,
or valuelength points outside the allocated address space of the process.
[ELOOP] A path name lookup involved too many symbolic links. [ENAMETOOLONG]
The length of path exceeds {MAXPATHLEN}, or a pathname component is longer
than {MAXNAMELEN}. attr_getf will fail if:
[ENOATTR] The attribute name
given is not associated with the indicated filesystem object. [E2BIG] The
value of the given attribute is too large to fit into the buffer. The integer
that the valuelength argument points to has been modified to show the actual
numnber of bytes that would be required to store the value of that attribute.
[EINVAL] A bit was set in the flag argument that is not defined for this
system call, or fd refers to a socket, not a file. [EFAULT] Attrname, attrvalue,
or valuelength points outside the allocated address space of the process.
[EBADF] Fd does not refer to a valid descriptor. DiagnosticsOn success,
zero is returned. On error, -1 is returned, and errno is set appropriately.
See Alsoattr(1), attr_multi(3), attr_remove(3), and attr_set(3).