/* Header file for command-reading library command.c.
   Copyright (C) 1986, 1989, 1990 Free Software Foundation, Inc.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#if !defined (COMMAND_H)
#define COMMAND_H 1

/* Not a set/show command.  Note that some commands which begin with
   "set" or "show" might be in this category, if their syntax does
   not fall into one of the following categories.  */
typedef enum cmd_types {
  not_set_cmd,
  set_cmd,
  show_cmd
} cmd_types;

/* Types of "set" or "show" command.  */
typedef enum var_types {
  /* "on" or "off".  *VAR is an integer which is nonzero for on,
     zero for off.  */
  var_boolean,
  /* Unsigned Integer.  *VAR is an unsigned int.  The user can type 0
     to mean "unlimited", which is stored in *VAR as UINT_MAX.  */
  var_uinteger,

  /* Like var_uinteger but signed.  *VAR is an int.  The user can type 0
     to mean "unlimited", which is stored in *VAR as INT_MAX.  */
  var_integer,

  /* String which the user enters with escapes (e.g. the user types \n and
     it is a real newline in the stored string).
     *VAR is a malloc'd string, or NULL if the string is empty.  */
  var_string,
  /* String which stores what the user types verbatim.
     *VAR is a malloc'd string, or NULL if the string is empty.  */
  var_string_noescape,
  /* String which stores a filename.
     *VAR is a malloc'd string, or NULL if the string is empty.  */
  var_filename,
  /* ZeroableInteger.  *VAR is an int.  Like Unsigned Integer except
     that zero really means zero.  */
  var_zinteger
} var_types;

/* This structure records one command'd definition.  */

struct cmd_list_element
  {
    /* Points to next command in this list.  */
    struct cmd_list_element *next;

    /* Name of this command.  */
    char *name;

    /* Command class; class values are chosen by application program.  */
    enum command_class class;

    /* Function definition of this command.
       Zero for command class names and for help topics that
       are not really commands.  */
    union {
	void (*cfunc) PARAMS ((char *args, int from_tty));
	void (*sfunc) PARAMS ((char *args, int from_tty,
			       struct cmd_list_element *c));
    } function;
#   define NO_FUNCTION ((void (*) PARAMS((char *args, int from_tty))) 0)

    /* Documentation of this command (or help topic).
       First line is brief documentation; remaining lines form, with it,
       the full documentation.  First line should end with a period.
       Entire string should also end with a period, not a newline.  */
    char *doc;

    /* Hook for another command to be executed before this command.  */
    struct cmd_list_element *hook;

    /* Nonzero identifies a prefix command.  For them, the address
       of the variable containing the list of subcommands.  */
    struct cmd_list_element **prefixlist;

    /* For prefix commands only:
       String containing prefix commands to get here: this one
       plus any others needed to get to it.  Should end in a space.
       It is used before the word "command" in describing the
       commands reached through this prefix.  */
    char *prefixname;

    /* For prefix commands only:
       nonzero means do not get an error if subcommand is not
       recognized; call the prefix's own function in that case.  */
    char allow_unknown;

    /* Nonzero says this is an abbreviation, and should not
       be mentioned in lists of commands.
       This allows "br<tab>" to complete to "break", which it
       otherwise wouldn't.  */
    char abbrev_flag;

    /* Completion routine for this command.  */
    char ** (*completer) PARAMS ((char *text));

    /* Type of "set" or "show" command (or SET_NOT_SET if not "set"
       or "show").  */
    cmd_types type;

    /* Pointer to variable affected by "set" and "show".  Doesn't matter
       if type is not_set.  */
    char *var;

    /* What kind of variable is *VAR?  */
    var_types var_type;

    /* Pointer to command strings of user-defined commands */
    struct command_line *user_commands;

    /* Pointer to command that is hooked by this one,
       so the hook can be removed when this one is deleted.  */
    struct cmd_list_element *hookee;

    /* Pointer to command that is aliased by this one, so the
       aliased command can be located in case it has been hooked.  */
    struct cmd_list_element *cmd_pointer;
  };

/* Forward-declarations of the entry-points of command.c.  */

extern struct cmd_list_element *
add_cmd PARAMS ((char *, enum command_class, void (*fun) (char *, int),
		 char *, struct cmd_list_element **));

extern struct cmd_list_element *
add_alias_cmd PARAMS ((char *, char *, enum command_class, int,
		       struct cmd_list_element **));

extern struct cmd_list_element *
add_prefix_cmd PARAMS ((char *, enum command_class, void (*fun) (char *, int),
			char *, struct cmd_list_element **, char *, int,
			struct cmd_list_element **));

extern struct cmd_list_element *
add_abbrev_prefix_cmd PARAMS ((char *, enum command_class,
			       void (*fun) (char *, int), char *,
			       struct cmd_list_element **, char *, int,
			       struct cmd_list_element **));

extern struct cmd_list_element *
lookup_cmd PARAMS ((char **, struct cmd_list_element *, char *, int, int));

extern struct cmd_list_element *
lookup_cmd_1 PARAMS ((char **, struct cmd_list_element *,
		      struct cmd_list_element **, int));

extern void
add_com PARAMS ((char *, enum command_class, void (*fun)(char *, int),
		 char *));

extern void
add_com_alias PARAMS ((char *, char *, enum command_class, int));

extern void
add_info PARAMS ((char *, void (*fun) (char *, int), char *));

extern void
add_info_alias PARAMS ((char *, char *, int));

extern char **
complete_on_cmdlist PARAMS ((struct cmd_list_element *, char *));

extern void
delete_cmd PARAMS ((char *, struct cmd_list_element **));

extern void
help_cmd PARAMS ((char *, FILE *));

extern void
help_list PARAMS ((struct cmd_list_element *, char *, enum command_class,
		   FILE *));

extern void
help_cmd_list PARAMS ((struct cmd_list_element *, enum command_class, char *,
		       int, FILE *));

extern struct cmd_list_element *
add_set_cmd PARAMS ((char *, enum command_class, var_types, char *, char *,
		     struct cmd_list_element **));

extern struct cmd_list_element *
add_show_from_set PARAMS ((struct cmd_list_element *,
			   struct cmd_list_element **));

/* Do a "set" or "show" command.  ARG is NULL if no argument, or the text
   of the argument, and FROM_TTY is nonzero if this command is being entered
   directly by the user (i.e. these are just like any other
   command).  C is the command list element for the command.  */

extern void
do_setshow_command PARAMS ((char *, int, struct cmd_list_element *));

/* Do a "show" command for each thing on a command list.  */

extern void
cmd_show_list PARAMS ((struct cmd_list_element *, int, char *));

extern void
error_no_arg PARAMS ((char *));

extern void
dont_repeat PARAMS ((void));

/* Used to mark commands that don't do anything.  If we just leave the
   function field NULL, the command is interpreted as a help topic, or
   as a class of commands.  */

extern void
not_just_help_class_command PARAMS ((char *, int));

#endif /* !defined (COMMAND_H) */
