try to overwrite the directory instead. An inverse makes the move-to-directory operation explicit. Moving versus copying and removing Moving files within the same file system is generally implemented differently than copying the file and then removing the original. On platforms that do not support the rename syscall, a new link is added to the new directory and the original one is deleted. The data of the file is not accessed. All POSIX-conformant systems implement the rename call. An actual move (effectively a rename) is dramatically faster than the circuitous copy-and-move procedure. The file's i-number (short for "inode number") does not change. No permission is required to read the file being moved insofar as—conceptually speaking—it is only information that is being changed as a result of the "move." Since the source and target directories are being modified, to wit, entries are being created within the target directory and erased from within the source directory, "write" permission in both directories is required to complete the move. Moving files from one file system to another may fail entirely or may be automatically performed as an atomic copy-and-delete action; the actual details are dependent upon the implementation. Moving a directory from one parent to a different parent directory requires write permission in the directory being moved, in addition to permissions to modify the old and new parents. This is because the i-number for the directory entry ".." (which can be used in any context as an alias for the parent of the current directory) changes as a result of the rename. Options Most versions of mv support: -i interactively process, write a prompt to standard error before moving a file that would overwrite an existing file. If the response from the standard input begins with the character 'y' or 'Y', the move is attempted. (Overrides previous -f option.) -f force overwriting the destination (overrides previous -i option). These options are a part of X/Open Portability Guidelines, later the basis of POSIX and SUS. All POSIX-compliant mv implementations must support these. Examples Note that, in the above example, /mnt referred to the directory (the "mount point") over which a given file system is mounted. Naming such directories /mnt is a popular convention but is by no means necessary. A "file system" can be thought of as an independent tree that is logically regarded as a unit; its root is "mounted" atop a directory of the