ATTR_SET(3)						       XFS Compatibility API						       ATTR_SET(3)

NAME

       attr_set, attr_setf - set the value of a user attribute of a filesystem object

C SYNOPSIS

       #include <attr/attributes.h>

       int attr_set (const char *path, const char *attrname,
		     const char *attrvalue, const int valuelength,
		     int flags);

       int attr_setf (int fd, const char *attrname,
		      const char *attrvalue, const int valuelength,
		      int flags);

DESCRIPTION

       The attr_set and attr_setf functions provide a way to create attributes and set/change their values.

       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
       does not exist, an attribute with the given name and value will be created and associated with that indicated  filesystem  object.   If	an
       attribute  with	that  name already exists on that filesystem object, the existing value is replaced with the new value given in this call.
       The new attribute value is copied from the attrvalue buffer for a total of valuelength bytes.  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_set function call.	The default is to follow symbolic links.

       ATTR_CREATE
	      Return  an  error  (EEXIST) if an attribute of the given name already exists on the indicated filesystem object, otherwise create an
	      attribute with the given name and value.	This flag is used to implement a pure create operation, without this  flag  attr_set  will
	      create  the attribute if it does not already exist.  An error (EINVAL) will be returned if both ATTR_CREATE and ATTR_REPLACE are set
	      in the same call.

       ATTR_REPLACE
	      Return an error (ENOATTR) if an attribute of the given name does not already exist on the  indicated  filesystem	object,  otherwise
	      replace  the  existing attribute's value with the given value.  This flag is used to implement a pure replacement operation, without
	      this flag attr_set will create the attribute if it does not already exist.  An error (EINVAL) will be returned if  both  ATTR_CREATE
	      and ATTR_REPLACE are set in the same call.

       attr_set will fail if one or more of the following are true:

       [ENOATTR]	The attribute name given is not associated with the indicated filesystem object and the ATTR_REPLACE flag bit was set.

       [E2BIG]		The value of the given attribute is too large, it exceeds the maximum allowable size of an attribute value.

       [EEXIST] 	The attribute name given is already associated with the indicated filesystem object and the ATTR_CREATE flag bit was set.

       [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, or both the ATTR_CREATE and ATTR_REPLACE
			flags bits were set.

       [EFAULT] 	Path, attrname, or attrvalue 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_setf will fail if:

       [ENOATTR]      The attribute name given is not associated with the indicated filesystem object and the ATTR_REPLACE flag bit was set.

       [E2BIG]	      The value of the given attribute is too large, it exceeds the maximum allowable size of an attribute value.

       [EEXIST]       The attribute name given is already associated with the indicated filesystem object and the ATTR_CREATE flag bit was set.

       [EINVAL]       A bit was set in the flag argument that is not defined for this system call, or both the ATTR_CREATE and ATTR_REPLACE  flags
		      bits were set, or fd refers to a socket, not a file.

       [EFAULT]       Attrname, or attrvalue points outside the allocated address space of the process.

       [EBADF]	      Fd does not refer to a valid descriptor.

DIAGNOSTICS

       On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.

SEE ALSO

       attr(1), attr_get(3), attr_list(3), attr_multi(3), and attr_remove(3).

Dec 2001							Extended Attributes						       ATTR_SET(3)