doc/hook/modify_command

SYNOPSIS
        #include <sys/driver_hooks.h>

        set_driver_hook(H_MODIFY_COMMAND, value)

        <value> being:

          int|string <closure>(string cmd, object player)
          int|string <name>(string cmd)
          <mapping>

DESCRIPTION
        Optional hook to modify commands (both entered or given by a
        call to command()) before the parser sees them.

        Hook setting can be any closure, the name of the function to
        call in the object, or a mapping.

        For interactives this hook is used only if the interactive
        object has no command modifier already set by the efun
        set_modify_command().

        If the hook is a closure, it is called with the entered
        command as first, and the command giving player as second
        argument. Unbound lambda closures are bound to the command
        giving player.

        If the hook is a string, it is used as the name of an lfun
        in the command giving player, which is called with the command
        as argument.

        If the hook is a mapping, it is queried with the given command
        as index, and the data retrieved is used as new command
        (defaults to 0 if no data is stored for a given command). If
        an entry is a closure instead of a string, it is called as

          int|string <closure>(string cmd, object player)

        and the result from the call is used as 'the' command.

        The result is treated equal in all three cases:
         - 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.

        It is possible for the hook to change the command giver
        (this_player()) for the execution of the command. This means that
        even though the commands are execute for the original commandgiver,
        this_player() will return the changed commandgiver.

HISTORY

SEE ALSO
        hooks(C), command(H), modify_command_fname(H), notify_fail(H),
        send_notify_fail(H)