variables.h

   1 /* variables.h -- data structures for shell variables. */
   2
   3 /* Copyright (C) 1987-2009 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bash is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #if !defined (_VARIABLES_H_)
  22 #define _VARIABLES_H_
  23
  24 #include "stdc.h"
  25 #include "array.h"
  26 #include "assoc.h"
  27
  28 /* Shell variables and functions are stored in hash tables. */
  29 #include "hashlib.h"
  30
  31 #include "conftypes.h"
  32
  33 /* A variable context. */
  34 typedef struct var_context {
  35   char *name;           /* empty or NULL means global context */
  36   int scope;            /* 0 means global context */
  37   int flags;
  38   struct var_context *up;       /* previous function calls */
  39   struct var_context *down;     /* down towards global context */
  40   HASH_TABLE *table;            /* variables at this scope */
  41 } VAR_CONTEXT;
  42
  43 /* Flags for var_context->flags */
  44 #define VC_HASLOCAL     0x01
  45 #define VC_HASTMPVAR    0x02
  46 #define VC_FUNCENV      0x04    /* also function if name != NULL */
  47 #define VC_BLTNENV      0x08    /* builtin_env */
  48 #define VC_TEMPENV      0x10    /* temporary_env */
  49
  50 #define VC_TEMPFLAGS    (VC_FUNCENV|VC_BLTNENV|VC_TEMPENV)
  51
  52 /* Accessing macros */
  53 #define vc_isfuncenv(vc)        (((vc)->flags & VC_FUNCENV) != 0)
  54 #define vc_isbltnenv(vc)        (((vc)->flags & VC_BLTNENV) != 0)
  55 #define vc_istempenv(vc)        (((vc)->flags & (VC_TEMPFLAGS)) == VC_TEMPENV)
  56
  57 #define vc_istempscope(vc)      (((vc)->flags & (VC_TEMPENV|VC_BLTNENV)) != 0)
  58
  59 #define vc_haslocals(vc)        (((vc)->flags & VC_HASLOCAL) != 0)
  60 #define vc_hastmpvars(vc)       (((vc)->flags & VC_HASTMPVAR) != 0)
  61
  62 /* What a shell variable looks like. */
  63
  64 typedef struct variable *sh_var_value_func_t __P((struct variable *));
  65 typedef struct variable *sh_var_assign_func_t __P((struct variable *, char *, arrayind_t, char *));
  66
  67 /* For the future */
  68 union _value {
  69   char *s;                      /* string value */
  70   intmax_t i;                   /* int value */
  71   COMMAND *f;                   /* function */
  72   ARRAY *a;                     /* array */
  73   HASH_TABLE *h;                /* associative array */
  74   double d;                     /* floating point number */
  75 #if defined (HAVE_LONG_DOUBLE)
  76   long double ld;               /* long double */
  77 #endif
  78   struct variable *v;           /* possible indirect variable use */
  79   void *opaque;                 /* opaque data for future use */
  80 };
  81
  82 typedef struct variable {
  83   char *name;                   /* Symbol that the user types. */
  84   char *value;                  /* Value that is returned. */
  85   char *exportstr;              /* String for the environment. */
  86   sh_var_value_func_t *dynamic_value;   /* Function called to return a `dynamic'
  87                                    value for a variable, like $SECONDS
  88                                    or $RANDOM. */
  89   sh_var_assign_func_t *assign_func; /* Function called when this `special
  90                                    variable' is assigned a value in
  91                                    bind_variable. */
  92   int attributes;               /* export, readonly, array, invisible... */
  93   int context;                  /* Which context this variable belongs to. */
  94 } SHELL_VAR;
  95
  96 typedef struct _vlist {
  97   SHELL_VAR **list;
  98   int list_size;        /* allocated size */
  99   int list_len;         /* current number of entries */
 100 } VARLIST;
 101
 102 /* The various attributes that a given variable can have. */
 103 /* First, the user-visible attributes */
 104 #define att_exported    0x0000001       /* export to environment */
 105 #define att_readonly    0x0000002       /* cannot change */
 106 #define att_array       0x0000004       /* value is an array */
 107 #define att_function    0x0000008       /* value is a function */
 108 #define att_integer     0x0000010       /* internal representation is int */
 109 #define att_local       0x0000020       /* variable is local to a function */
 110 #define att_assoc       0x0000040       /* variable is an associative array */
 111 #define att_trace       0x0000080       /* function is traced with DEBUG trap */
 112 #define att_uppercase   0x0000100       /* word converted to uppercase on assignment */
 113 #define att_lowercase   0x0000200       /* word converted to lowercase on assignment */
 114 #define att_capcase     0x0000400       /* word capitalized on assignment */
 115
 116 #define user_attrs      (att_exported|att_readonly|att_integer|att_local|att_trace|att_uppercase|att_lowercase|att_capcase)
 117
 118 #define attmask_user    0x0000fff
 119
 120 /* Internal attributes used for bookkeeping */
 121 #define att_invisible   0x0001000       /* cannot see */
 122 #define att_nounset     0x0002000       /* cannot unset */
 123 #define att_noassign    0x0004000       /* assignment not allowed */
 124 #define att_imported    0x0008000       /* came from environment */
 125 #define att_special     0x0010000       /* requires special handling */
 126 #define att_nofree      0x0020000       /* do not free value on unset */
 127
 128 #define attmask_int     0x00ff000
 129
 130 /* Internal attributes used for variable scoping. */
 131 #define att_tempvar     0x0100000       /* variable came from the temp environment */
 132 #define att_propagate   0x0200000       /* propagate to previous scope */
 133
 134 #define attmask_scope   0x0f00000
 135
 136 #define exported_p(var)         ((((var)->attributes) & (att_exported)))
 137 #define readonly_p(var)         ((((var)->attributes) & (att_readonly)))
 138 #define array_p(var)            ((((var)->attributes) & (att_array)))
 139 #define function_p(var)         ((((var)->attributes) & (att_function)))
 140 #define integer_p(var)          ((((var)->attributes) & (att_integer)))
 141 #define local_p(var)            ((((var)->attributes) & (att_local)))
 142 #define assoc_p(var)            ((((var)->attributes) & (att_assoc)))
 143 #define trace_p(var)            ((((var)->attributes) & (att_trace)))
 144 #define uppercase_p(var)        ((((var)->attributes) & (att_uppercase)))
 145 #define lowercase_p(var)        ((((var)->attributes) & (att_lowercase)))
 146 #define capcase_p(var)          ((((var)->attributes) & (att_capcase)))
 147
 148 #define invisible_p(var)        ((((var)->attributes) & (att_invisible)))
 149 #define non_unsettable_p(var)   ((((var)->attributes) & (att_nounset)))
 150 #define noassign_p(var)         ((((var)->attributes) & (att_noassign)))
 151 #define imported_p(var)         ((((var)->attributes) & (att_imported)))
 152 #define specialvar_p(var)       ((((var)->attributes) & (att_special)))
 153 #define nofree_p(var)           ((((var)->attributes) & (att_nofree)))
 154
 155 #define tempvar_p(var)          ((((var)->attributes) & (att_tempvar)))
 156
 157 /* Acessing variable values: rvalues */
 158 #define value_cell(var)         ((var)->value)
 159 #define function_cell(var)      (COMMAND *)((var)->value)
 160 #define array_cell(var)         (ARRAY *)((var)->value)
 161 #define assoc_cell(var)         (HASH_TABLE *)((var)->value)
 162
 163 #define var_isnull(var)         ((var)->value == 0)
 164 #define var_isset(var)          ((var)->value != 0)
 165
 166 /* Assigning variable values: lvalues */
 167 #define var_setvalue(var, str)  ((var)->value = (str))
 168 #define var_setfunc(var, func)  ((var)->value = (char *)(func))
 169 #define var_setarray(var, arr)  ((var)->value = (char *)(arr))
 170 #define var_setassoc(var, arr)  ((var)->value = (char *)(arr))
 171
 172 /* Make VAR be auto-exported. */
 173 #define set_auto_export(var) \
 174   do { (var)->attributes |= att_exported; array_needs_making = 1; } while (0)
 175
 176 #define SETVARATTR(var, attr, undo) \
 177         ((undo == 0) ? ((var)->attributes |= (attr)) \
 178                      : ((var)->attributes &= ~(attr)))
 179
 180 #define VSETATTR(var, attr)     ((var)->attributes |= (attr))
 181 #define VUNSETATTR(var, attr)   ((var)->attributes &= ~(attr))
 182
 183 #define VGETFLAGS(var)          ((var)->attributes)
 184
 185 #define VSETFLAGS(var, flags)   ((var)->attributes = (flags))
 186 #define VCLRFLAGS(var)          ((var)->attributes = 0)
 187
 188 /* Macros to perform various operations on `exportstr' member of a SHELL_VAR. */
 189 #define CLEAR_EXPORTSTR(var)    (var)->exportstr = (char *)NULL
 190 #define COPY_EXPORTSTR(var)     ((var)->exportstr) ? savestring ((var)->exportstr) : (char *)NULL
 191 #define SET_EXPORTSTR(var, value)  (var)->exportstr = (value)
 192 #define SAVE_EXPORTSTR(var, value) (var)->exportstr = (value) ? savestring (value) : (char *)NULL
 193
 194 #define FREE_EXPORTSTR(var) \
 195         do { if ((var)->exportstr) free ((var)->exportstr); } while (0)
 196
 197 #define CACHE_IMPORTSTR(var, value) \
 198         (var)->exportstr = savestring (value)
 199
 200 #define INVALIDATE_EXPORTSTR(var) \
 201         do { \
 202           if ((var)->exportstr) \
 203             { \
 204               free ((var)->exportstr); \
 205               (var)->exportstr = (char *)NULL; \
 206             } \
 207         } while (0)
 208
 209 /* Stuff for hacking variables. */
 210 typedef int sh_var_map_func_t __P((SHELL_VAR *));
 211
 212 /* Where we keep the variables and functions */
 213 extern VAR_CONTEXT *global_variables;
 214 extern VAR_CONTEXT *shell_variables;
 215
 216 extern HASH_TABLE *shell_functions;
 217 extern HASH_TABLE *temporary_env;
 218
 219 extern int variable_context;
 220 extern char *dollar_vars[];
 221 extern char **export_env;
 222
 223 extern void initialize_shell_variables __P((char **, int));
 224 extern SHELL_VAR *set_if_not __P((char *, char *));
 225
 226 extern void sh_set_lines_and_columns __P((int, int));
 227 extern void set_pwd __P((void));
 228 extern void set_ppid __P((void));
 229 extern void make_funcname_visible __P((int));
 230
 231 extern SHELL_VAR *var_lookup __P((const char *, VAR_CONTEXT *));
 232
 233 extern SHELL_VAR *find_function __P((const char *));
 234 extern FUNCTION_DEF *find_function_def __P((const char *));
 235 extern SHELL_VAR *find_variable __P((const char *));
 236 extern SHELL_VAR *find_variable_internal __P((const char *, int));
 237 extern SHELL_VAR *find_tempenv_variable __P((const char *));
 238 extern SHELL_VAR *copy_variable __P((SHELL_VAR *));
 239 extern SHELL_VAR *make_local_variable __P((const char *));
 240 extern SHELL_VAR *bind_variable __P((const char *, char *, int));
 241 extern SHELL_VAR *bind_function __P((const char *, COMMAND *));
 242
 243 extern void bind_function_def __P((const char *, FUNCTION_DEF *));
 244
 245 extern SHELL_VAR **map_over __P((sh_var_map_func_t *, VAR_CONTEXT *));
 246 SHELL_VAR **map_over_funcs __P((sh_var_map_func_t *));
 247
 248 extern SHELL_VAR **all_shell_variables __P((void));
 249 extern SHELL_VAR **all_shell_functions __P((void));
 250 extern SHELL_VAR **all_visible_variables __P((void));
 251 extern SHELL_VAR **all_visible_functions __P((void));
 252 extern SHELL_VAR **all_exported_variables __P((void));
 253 extern SHELL_VAR **local_exported_variables __P((void));
 254 extern SHELL_VAR **all_local_variables __P((void));
 255 #if defined (ARRAY_VARS)
 256 extern SHELL_VAR **all_array_variables __P((void));
 257 #endif
 258 extern char **all_variables_matching_prefix __P((const char *));
 259
 260 extern char **make_var_array __P((HASH_TABLE *));
 261 extern char **add_or_supercede_exported_var __P((char *, int));
 262
 263 extern char *get_variable_value __P((SHELL_VAR *));
 264 extern char *get_string_value __P((const char *));
 265 extern char *sh_get_env_value __P((const char *));
 266 extern char *make_variable_value __P((SHELL_VAR *, char *, int));
 267
 268 extern SHELL_VAR *bind_variable_value __P((SHELL_VAR *, char *, int));
 269 extern SHELL_VAR *bind_int_variable __P((char *, char *));
 270 extern SHELL_VAR *bind_var_to_int __P((char *, intmax_t));
 271
 272 extern int assign_in_env __P((WORD_DESC *));
 273
 274 extern int unbind_variable __P((const char *));
 275 extern int unbind_func __P((const char *));
 276 extern int unbind_function_def __P((const char *));
 277 extern int makunbound __P((const char *, VAR_CONTEXT *));
 278 extern int kill_local_variable __P((const char *));
 279 extern void delete_all_variables __P((HASH_TABLE *));
 280 extern void delete_all_contexts __P((VAR_CONTEXT *));
 281
 282 extern VAR_CONTEXT *new_var_context __P((char *, int));
 283 extern void dispose_var_context __P((VAR_CONTEXT *));
 284 extern VAR_CONTEXT *push_var_context __P((char *, int, HASH_TABLE *));
 285 extern void pop_var_context __P((void));
 286 extern VAR_CONTEXT *push_scope __P((int, HASH_TABLE *));
 287 extern void pop_scope __P((int));
 288
 289 extern void push_context __P((char *, int, HASH_TABLE *));
 290 extern void pop_context __P((void));
 291 extern void push_dollar_vars __P((void));
 292 extern void pop_dollar_vars __P((void));
 293 extern void dispose_saved_dollar_vars __P((void));
 294
 295 extern void push_args __P((WORD_LIST *));
 296 extern void pop_args __P((void));
 297
 298 extern void adjust_shell_level __P((int));
 299 extern void non_unsettable __P((char *));
 300 extern void dispose_variable __P((SHELL_VAR *));
 301 extern void dispose_used_env_vars __P((void));
 302 extern void dispose_function_env __P((void));
 303 extern void dispose_builtin_env __P((void));
 304 extern void merge_temporary_env __P((void));
 305 extern void merge_builtin_env __P((void));
 306 extern void kill_all_local_variables __P((void));
 307
 308 extern void set_var_read_only __P((char *));
 309 extern void set_func_read_only __P((const char *));
 310 extern void set_var_auto_export __P((char *));
 311 extern void set_func_auto_export __P((const char *));
 312
 313 extern void sort_variables __P((SHELL_VAR **));
 314
 315 extern void maybe_make_export_env __P((void));
 316 extern void update_export_env_inplace __P((char *, int, char *));
 317 extern void put_command_name_into_env __P((char *));
 318 extern void put_gnu_argv_flags_into_env __P((intmax_t, char *));
 319
 320 extern void print_var_list __P((SHELL_VAR **));
 321 extern void print_func_list __P((SHELL_VAR **));
 322 extern void print_assignment __P((SHELL_VAR *));
 323 extern void print_var_value __P((SHELL_VAR *, int));
 324 extern void print_var_function __P((SHELL_VAR *));
 325
 326 #if defined (ARRAY_VARS)
 327 extern SHELL_VAR *make_new_array_variable __P((char *));
 328 extern SHELL_VAR *make_local_array_variable __P((char *));
 329
 330 extern SHELL_VAR *make_new_assoc_variable __P((char *));
 331 extern SHELL_VAR *make_local_assoc_variable __P((char *));
 332
 333 extern void set_pipestatus_array __P((int *, int));
 334 #endif
 335
 336 extern void set_pipestatus_from_exit __P((int));
 337
 338 /* The variable in NAME has just had its state changed.  Check to see if it
 339    is one of the special ones where something special happens. */
 340 extern void stupidly_hack_special_variables __P((char *));
 341
 342 /* Reinitialize some special variables that have external effects upon unset
 343    when the shell reinitializes itself. */
 344 extern void reinit_special_variables __P((void));
 345
 346 extern int get_random_number __P((void));
 347
 348 /* The `special variable' functions that get called when a particular
 349    variable is set. */
 350 extern void sv_ifs __P((char *));
 351 extern void sv_path __P((char *));
 352 extern void sv_mail __P((char *));
 353 extern void sv_globignore __P((char *));
 354 extern void sv_ignoreeof __P((char *));
 355 extern void sv_strict_posix __P((char *));
 356 extern void sv_optind __P((char *));
 357 extern void sv_opterr __P((char *));
 358 extern void sv_locale __P((char *));
 359 extern void sv_xtracefd __P((char *));
 360
 361 #if defined (READLINE)
 362 extern void sv_comp_wordbreaks __P((char *));
 363 extern void sv_terminal __P((char *));
 364 extern void sv_hostfile __P((char *));
 365 extern void sv_winsize __P((char *));
 366 #endif
 367
 368 #if defined (__CYGWIN__)
 369 extern void sv_home __P((char *));
 370 #endif
 371
 372 #if defined (HISTORY)
 373 extern void sv_histsize __P((char *));
 374 extern void sv_histignore __P((char *));
 375 extern void sv_history_control __P((char *));
 376 #  if defined (BANG_HISTORY)
 377 extern void sv_histchars __P((char *));
 378 #  endif
 379 extern void sv_histtimefmt __P((char *));
 380 #endif /* HISTORY */
 381
 382 #if defined (HAVE_TZSET) && defined (PROMPT_STRING_DECODE)
 383 extern void sv_tz __P((char *));
 384 #endif
 385
 386 #endif /* !_VARIABLES_H_ */