text: /* variables.h -- data structures for shell variables. */
  
  /* Copyright (C) 1987,1991 Free Software Foundation, Inc.
  
     This file is part of GNU Bash, the Bourne Again SHell.
  
     Bash 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, or (at your option)
     any later version.
  
     Bash 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 Bash; see the file COPYING.  If not, write to the Free
     Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  
  #if !defined (_VARIABLES_H_)
  #define _VARIABLES_H_
  
  #include "stdc.h"
  #include "array.h"
  
  /* Shell variables and functions are stored in hash tables. */
  #include "hashlib.h"
  
  /* Placeholder for future modifications if cross-compiling or building a
     `fat' binary, e.g. on Apple Rhapsody.  These values are used in multiple
     files, so they appear here. */
  #if !defined (RHAPSODY)
  #  define HOSTTYPE	CONF_HOSTTYPE
  #  define OSTYPE	CONF_OSTYPE
  #  define MACHTYPE	CONF_MACHTYPE
  #else /* RHAPSODY */
  #  if   defined(__powerpc__) || defined(__ppc__)
  #    define HOSTTYPE "powerpc"
  #  elif defined(__i386__)
  #    define HOSTTYPE "i386"
  #  else
  #    define HOSTTYPE CONF_HOSTTYPE
  #  endif
  
  #  define OSTYPE CONF_OSTYPE
  #  define VENDOR CONF_VENDOR
  
  #  define MACHTYPE HOSTTYPE "-" VENDOR "-" OSTYPE
  #endif /* RHAPSODY */
  
  /* 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. */
    char *exportstr;		/* String for the environment. */
    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. */
  #define att_exported  0x001	/* export to environment */
  #define att_readonly  0x002	/* cannot change */
  #define att_invisible 0x004	/* cannot see */
  #define att_array     0x008	/* value is an array */
  #define att_nounset   0x010	/* cannot unset */
  #define att_function  0x020	/* value is a function */
  #define att_integer   0x040	/* internal representation is int */
  #define att_imported  0x080	/* came from environment */
  #define att_local     0x100	/* variable is local to a function */
  #define att_tempvar   0x200	/* variable came from the temp environment */
  #define att_importstr 0x400	/* exportstr points into initial environment */
  #define att_noassign  0x800	/* assignment not allowed */
  
  #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 non_unsettable_p(var)	((((var)->attributes) & (att_nounset)))
  #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 local_p(var)		((((var)->attributes) & (att_local)))
  #define tempvar_p(var)		((((var)->attributes) & (att_tempvar)))
  #define noassign_p(var)		((((var)->attributes) & (att_noassign)))
  
  #define value_cell(var) ((var)->value)
  #define function_cell(var) (COMMAND *)((var)->value)
  #define array_cell(var) ((ARRAY *)(var)->value)
  
  #define SETVARATTR(var, attr, undo) \
  	((undo == 0) ? ((var)->attributes |= (attr)) \
  		     : ((var)->attributes &= ~(attr)))
  
  #define VSETATTR(var, attr)	((var)->attributes |= (attr))
  #define VUNSETATTR(var, attr)	((var)->attributes &= ~(attr))
  
  /* Macros to perform various operations on `exportstr' member of a SHELL_VAR. */
  #define CLEAR_EXPORTSTR(var)	(var)->exportstr = (char *)NULL
  #define COPY_EXPORTSTR(var)	((var)->exportstr) ? savestring ((var)->exportstr) : (char *)NULL
  #define SET_EXPORTSTR(var, value)  (var)->exportstr = (value)
  #define SAVE_EXPORTSTR(var, value) (var)->exportstr = (value) ? savestring (value) : (char *)NULL
  
  #define FREE_EXPORTSTR(var) \
  	do { \
  	  if ((var)->exportstr) \
  	    { \
  	      if (((var)->attributes & att_importstr) == 0) \
  		free ((var)->exportstr); \
  	    } \
  	} while (0)
  
  #if 0
  #define CACHE_IMPORTSTR(var, value) \
  	do { \
  	  (var)->exportstr = value; \
  	  (var)->attributes |= att_importstr; \
  	} while (0)
  #else
  #define CACHE_IMPORTSTR(var, value) \
  	do { \
  	  (var)->exportstr = savestring (value); \
  	} while (0)
  #endif
  
  #define INVALIDATE_EXPORTSTR(var) \
  	do { \
  	  if ((var)->exportstr) \
  	    { \
  	      if (((var)->attributes & att_importstr) == 0) \
  		free ((var)->exportstr); \
  	      (var)->exportstr = (char *)NULL; \
  	      (var)->attributes &= ~att_importstr; \
  	    } \
  	} while (0)
  	
  /* 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 **, int));
  extern SHELL_VAR *set_if_not __P((char *, char *));
  extern void sh_set_lines_and_columns __P((int, int));
  
  extern void set_pwd __P((void));
  
  extern void set_ppid __P((void));
  
  extern void make_funcname_visible __P((int));
  
  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 *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 SHELL_VAR **all_exported_variables __P((void));
  #if defined (ARRAY_VARS)
  extern SHELL_VAR **all_array_variables __P((void));
  #endif
  
  extern char **all_variables_matching_prefix __P((char *));
  
  extern char **make_var_array __P((HASH_TABLE *));
  extern char **add_or_supercede_exported_var __P((char *, int));
  
  extern char *get_string_value __P((const char *));
  extern char *make_variable_value __P((SHELL_VAR *, char *));
  
  extern SHELL_VAR *bind_variable_value __P((SHELL_VAR *, char *));
  extern SHELL_VAR *bind_int_variable __P((char *, 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_used_env_vars __P((void));
  extern void dispose_function_env __P((void));
  extern void dispose_builtin_env __P((void));
  extern void merge_temporary_env __P((void));
  extern void merge_builtin_env __P((void));
  extern void merge_function_env __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_variables __P((SHELL_VAR **));
  extern void maybe_make_export_env __P((void));
  extern void update_export_env_inplace __P((char *, int, char *));
  extern void put_command_name_into_env __P((char *));
  extern void put_gnu_argv_flags_into_env __P((int, char *));
  extern void print_var_list __P((SHELL_VAR **));
  extern void print_func_list __P((SHELL_VAR **));
  extern void print_assignment __P((SHELL_VAR *));
  extern void print_var_value __P((SHELL_VAR *, int));
  extern void print_var_function __P((SHELL_VAR *));
  
  extern char *indirection_level_string __P((void));
  
  #if defined (ARRAY_VARS)
  extern SHELL_VAR *make_new_array_variable __P((char *));
  extern SHELL_VAR *make_local_array_variable __P((char *));
  extern SHELL_VAR *convert_var_to_array __P((SHELL_VAR *));
  extern SHELL_VAR *bind_array_variable __P((char *, int, char *));
  extern SHELL_VAR *assign_array_from_string  __P((char *, char *));
  extern SHELL_VAR *assign_array_var_from_word_list __P((SHELL_VAR *, WORD_LIST *));
  extern SHELL_VAR *assign_array_var_from_string __P((SHELL_VAR *, char *));
  extern int unbind_array_element __P((SHELL_VAR *, char *));
  extern int skipsubscript __P((char *, int));
  extern void print_array_assignment __P((SHELL_VAR *, int));
  
  extern void set_pipestatus_array __P((int *));
  #endif
  
  extern void set_pipestatus_from_exit __P((int));
  
  /* The variable in NAME has just had its state changed.  Check to see if it
     is one of the special ones where something special happens. */
  extern void stupidly_hack_special_variables __P((char *));
  
  extern int get_random_number __P((void));
  
  /* The `special variable' functions that get called when a particular
     variable is set. */
  void sv_path (), sv_mail (), sv_ignoreeof (), sv_strict_posix ();
  void sv_optind (), sv_opterr (), sv_globignore (), sv_locale ();
  
  #if defined (READLINE)
  void sv_terminal (), sv_hostfile ();
  #endif
  
  #if defined (HAVE_TZSET) && defined (PROMPT_STRING_DECODE)
  void sv_tz ();
  #endif
  
  #if defined (HISTORY)
  void sv_histsize (), sv_histignore (), sv_history_control ();
  #  if defined (BANG_HISTORY)
  void sv_histchars ();
  #  endif
  #endif /* HISTORY */
  
  #endif /* !_VARIABLES_H_ */
  