/* variables.h -- data structures for shell variables. */

#if !defined (_VARIABLES_H_)
#define _VARIABLES_H_

#include "stdc.h"

/* Shell variables and functions are stored in hash tables. */
#include "hash.h"

/* What a shell variable looks like. */

typedef struct variable *DYNAMIC_FUNC ();

typedef struct variable {
  char *name;			/* Symbol that the user types. */
  char *value;			/* Value that is returned. */
  DYNAMIC_FUNC *dynamic_value;	/* Function called to return a `dynamic'
				   value for a variable, like $SECONDS
				   or $RANDOM. */
  DYNAMIC_FUNC *assign_func; 	/* Function called when this `special
				   variable' is assigned a value in
				   bind_variable. */
  int attributes;		/* export, readonly, array, invisible... */
  int context;			/* Which context this variable belongs to. */
  struct variable *prev_context; /* Value from previous context or NULL. */
} SHELL_VAR;

/* The various attributes that a given variable can have.
   We only reserve one byte of the INT. */
#define att_exported  0x01	/* %00000001 (export to environment) */
#define att_readonly  0x02	/* %00000010 (cannot change)	     */
#define att_invisible 0x04	/* %00000100 (cannot see)	     */
#define att_array     0x08	/* %00001000 (value is an array)     */
#define att_nounset   0x10	/* %00010000 (cannot unset)	     */
#define att_function  0x20	/* %00100000 (value is a function)   */
#define att_integer   0x40	/* %01000000 (internal rep. is int)  */
#define att_imported  0x80	/* %10000000 (came from environment) */

#define exported_p(var)		((((var)->attributes) & (att_exported)))
#define readonly_p(var)		((((var)->attributes) & (att_readonly)))
#define invisible_p(var)	((((var)->attributes) & (att_invisible)))
#define array_p(var)		((((var)->attributes) & (att_array)))
#define function_p(var)		((((var)->attributes) & (att_function)))
#define integer_p(var)		((((var)->attributes) & (att_integer)))
#define imported_p(var)         ((((var)->attributes) & (att_imported)))

#define value_cell(var) ((var)->value)
#define function_cell(var) (COMMAND *)((var)->value)

/* Stuff for hacking variables. */
extern int variable_context;
extern HASH_TABLE *shell_variables, *shell_functions;
extern char *dollar_vars[];
extern char **export_env;
extern char **non_unsettable_vars;

extern void initialize_shell_variables __P((char **));

extern SHELL_VAR *find_function __P((char *));
extern SHELL_VAR *find_variable __P((char *));
extern SHELL_VAR *find_variable_internal __P((char *, int));
extern SHELL_VAR *find_tempenv_variable __P((char *));
extern SHELL_VAR *copy_variable __P((SHELL_VAR *));
extern SHELL_VAR *set_if_not __P((char *, char *));
extern SHELL_VAR *make_local_variable __P((char *));
extern SHELL_VAR *bind_variable __P((char *, char *));
extern SHELL_VAR *bind_function __P((char *, COMMAND *));
extern SHELL_VAR **map_over __P((Function *, HASH_TABLE *));
extern SHELL_VAR **all_shell_variables __P((void));
extern SHELL_VAR **all_shell_functions __P((void));
extern SHELL_VAR **all_visible_variables __P((void));
extern SHELL_VAR **all_visible_functions __P((void));

extern char **make_var_array __P((HASH_TABLE *));
extern char **add_or_supercede __P((char *, char **));

extern char *get_string_value __P((char *));

extern int assignment __P((char *));
extern int variable_in_context __P((SHELL_VAR *));
extern int assign_in_env __P((char *));
extern int unbind_variable __P((char *));
extern int makunbound __P((char *, HASH_TABLE *));
extern int kill_local_variable __P((char *));
extern void delete_all_variables __P((HASH_TABLE *));

extern void adjust_shell_level __P((int));
extern void non_unsettable __P((char *));
extern void dispose_variable __P((SHELL_VAR *));
extern void dispose_function_env __P((void));
extern void dispose_builtin_env __P((void));
extern void dispose_used_env_vars __P((void));
extern void kill_all_local_variables __P((void));
extern void set_var_read_only __P((char *));
extern void set_func_read_only __P((char *));
extern void set_var_auto_export __P((char *));
extern void set_func_auto_export __P((char *));
extern void sort_char_array __P((char **));
extern void sort_variables __P((SHELL_VAR **));
extern void maybe_make_export_env __P((void));
extern void put_command_name_into_env __P((char *));
extern void print_var_list __P((SHELL_VAR **));
extern void print_assignment __P((SHELL_VAR *));
extern void print_var_value __P((SHELL_VAR *));
extern void print_var_function __P((SHELL_VAR *));

#endif /* !_VARIABLES_H_ */