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//go:build freebsd
package system
import (
"os"
"unsafe"
"golang.org/x/sys/unix"
)
const (
EXTATTR_NAMESPACE_EMPTY = unix.EXTATTR_NAMESPACE_EMPTY
EXTATTR_NAMESPACE_USER = unix.EXTATTR_NAMESPACE_USER
EXTATTR_NAMESPACE_SYSTEM = unix.EXTATTR_NAMESPACE_SYSTEM
)
// ExtattrGetLink retrieves the value of the extended attribute identified by attrname
// in the given namespace and associated with the given path in the file system.
// If the path is a symbolic link, the extended attribute is retrieved from the link itself.
// Returns a []byte slice if the extattr is set and nil otherwise.
func ExtattrGetLink(path string, attrnamespace int, attrname string) ([]byte, error) {
size, errno := unix.ExtattrGetLink(path, attrnamespace, attrname,
uintptr(unsafe.Pointer(nil)), 0)
if errno != nil {
if errno == unix.ENOATTR {
return nil, nil
}
return nil, &os.PathError{Op: "extattr_get_link", Path: path, Err: errno}
}
if size == 0 {
return []byte{}, nil
}
dest := make([]byte, size)
size, errno = unix.ExtattrGetLink(path, attrnamespace, attrname,
uintptr(unsafe.Pointer(&dest[0])), size)
if errno != nil {
return nil, &os.PathError{Op: "extattr_get_link", Path: path, Err: errno}
}
return dest[:size], nil
}
// ExtattrSetLink sets the value of extended attribute identified by attrname
// in the given namespace and associated with the given path in the file system.
// If the path is a symbolic link, the extended attribute is set on the link itself.
func ExtattrSetLink(path string, attrnamespace int, attrname string, data []byte) error {
if len(data) == 0 {
data = []byte{} // ensure non-nil for empty data
}
if _, errno := unix.ExtattrSetLink(path, attrnamespace, attrname,
uintptr(unsafe.Pointer(&data[0])), len(data)); errno != nil {
return &os.PathError{Op: "extattr_set_link", Path: path, Err: errno}
}
return nil
}
// ExtattrListLink lists extended attributes associated with the given path
// in the specified namespace. If the path is a symbolic link, the attributes
// are listed from the link itself.
func ExtattrListLink(path string, attrnamespace int) ([]string, error) {
size, errno := unix.ExtattrListLink(path, attrnamespace,
uintptr(unsafe.Pointer(nil)), 0)
if errno != nil {
return nil, &os.PathError{Op: "extattr_list_link", Path: path, Err: errno}
}
if size == 0 {
return []string{}, nil
}
dest := make([]byte, size)
size, errno = unix.ExtattrListLink(path, attrnamespace,
uintptr(unsafe.Pointer(&dest[0])), size)
if errno != nil {
return nil, &os.PathError{Op: "extattr_list_link", Path: path, Err: errno}
}
var attrs []string
for i := 0; i < size; {
// Each attribute is preceded by a single byte length
length := int(dest[i])
i++
if i+length > size {
break
}
attrs = append(attrs, string(dest[i:i+length]))
i += length
}
return attrs, nil
}
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