shared/util_linux.go
func GetAllXattr(path string) (xattrs map[string]string, err error) {
	e1 := fmt.Errorf("Extended attributes changed during retrieval")

	// Call llistxattr() twice: First, to determine the size of the buffer
	// we need to allocate to store the extended attributes, second, to
	// actually store the extended attributes in the buffer. Also, check if
	// the size/number of extended attributes hasn't changed between the two
	// calls.
	pre, err := llistxattr(path, nil)
	if err != nil || pre < 0 {
		return nil, err
	}
	if pre == 0 {
		return nil, nil
	}

	dest := make([]byte, pre)

	post, err := llistxattr(path, dest)
	if err != nil || post < 0 {
		return nil, err
	}
	if post != pre {
		return nil, e1
	}

	split := strings.Split(string(dest), "\x00")
	if split == nil {
		return nil, fmt.Errorf("No valid extended attribute key found")
	}
	// *listxattr functions return a list of  names  as  an unordered array
	// of null-terminated character strings (attribute names are separated
	// by null bytes ('\0')), like this: user.name1\0system.name1\0user.name2\0
	// Since we split at the '\0'-byte the last element of the slice will be
	// the empty string. We remove it:
	if split[len(split)-1] == "" {
		split = split[:len(split)-1]
	}

	xattrs = make(map[string]string, len(split))

	for _, x := range split {
		xattr := string(x)
		// Call Getxattr() twice: First, to determine the size of the
		// buffer we need to allocate to store the extended attributes,
		// second, to actually store the extended attributes in the
		// buffer. Also, check if the size of the extended attribute
		// hasn't changed between the two calls.
		pre, err = syscall.Getxattr(path, xattr, nil)
		if err != nil || pre < 0 {
			return nil, err
		}

		dest = make([]byte, pre)
		post := 0
		if pre > 0 {
			post, err = syscall.Getxattr(path, xattr, dest)
			if err != nil || post < 0 {
				return nil, err
			}
		}

		if post != pre {
			return nil, e1
		}

		xattrs[xattr] = string(dest)
	}

	return xattrs, nil
}
func GetAllXattr(path string) (xattrs map[string]string, err error) {
	e1 := fmt.Errorf("Extended attributes changed during retrieval")

	// Call llistxattr() twice: First, to determine the size of the buffer
	// we need to allocate to store the extended attributes, second, to
	// actually store the extended attributes in the buffer. Also, check if
	// the size/number of extended attributes hasn't changed between the two
	// calls.
	pre, err := llistxattr(path, nil)
	if err != nil || pre < 0 {
		return nil, err
	}
	if pre == 0 {
		return nil, nil
	}

	dest := make([]byte, pre)

	post, err := llistxattr(path, dest)
	if err != nil || post < 0 {
		return nil, err
	}
	if post != pre {
		return nil, e1
	}

	split := strings.Split(string(dest), "\x00")
	if split == nil {
		return nil, fmt.Errorf("No valid extended attribute key found")
	}
	// *listxattr functions return a list of  names  as  an unordered array
	// of null-terminated character strings (attribute names are separated
	// by null bytes ('\0')), like this: user.name1\0system.name1\0user.name2\0
	// Since we split at the '\0'-byte the last element of the slice will be
	// the empty string. We remove it:
	if split[len(split)-1] == "" {
		split = split[:len(split)-1]
	}

	xattrs = make(map[string]string, len(split))

	for _, x := range split {
		xattr := string(x)
		// Call Getxattr() twice: First, to determine the size of the
		// buffer we need to allocate to store the extended attributes,
		// second, to actually store the extended attributes in the
		// buffer. Also, check if the size of the extended attribute
		// hasn't changed between the two calls.
		pre, err = syscall.Getxattr(path, xattr, nil)
		if err != nil || pre < 0 {
			return nil, err
		}

		dest = make([]byte, pre)
		post := 0
		if pre > 0 {
			post, err = syscall.Getxattr(path, xattr, dest)
			if err != nil || post < 0 {
				return nil, err
			}
		}

		if post != pre {
			return nil, e1
		}

		xattrs[xattr] = string(dest)
	}

	return xattrs, nil
}
// GetAllXattr retrieves all extended attributes associated with a file,
// directory or symbolic link.