Интерактивная система просмотра системных руководств (man-ов)
attr_setf (3)
>> attr_setf (3) ( Linux man: Библиотечные вызовы )
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.
