SYNOPSIS
        int|string modify_command(string cmd)

DESCRIPTION
        After set_modify_command(mob) was called for an interactive
        object iob, all commands for that user will be passed to
        mob->modify_command(), and the return will then be checked for
        actions.

        If the result is a string, it is the new command to execute
        instead of the given one. Note that it is not possible to
        make several commands from one this way!
        If the result is a non-zero number, the given command is to
        be ignored. In case of the closure/lfun setting this may
        mean that the closure/lfun already executed it.
        If the result is 0, the originally given command is to be
        used.

HISTORY
        In 3.2.1@109 the name of the lfun to call must be specified
        using the H_MODIFY_COMMAND_FNAME driver hook.
        'modify_command' in the above text is therefore to read as
        placeholder for the real name.


SEE ALSO
        set_modify_command(E), hooks(C)