@end deftypefn
@deftypefn {System Call} int inumber (int @var{fd})
-Returns the @dfn{inode number} of the inode associated with @var{fd}.
-Applicable to file descriptors for both files and directories.
+Returns the @dfn{inode number} of the inode associated with @var{fd},
+which may represent an ordinary file or a directory.
An inode number persistently identifies a file or directory. It is
unique during the file's existence. In Pintos, the sector number of the